The performance of a solenoid drive liquid pump can be very dependent on the magnitude and stability of an input voltage, with non-ideal input power resulting in loss of efficiency and potential damage to the pump. Pulse width of drive signals provided to the pump, which cause solenoids to alternately energize to move liquid through the pump, may be adjusted in duration in order to compensate for non-ideal input voltage. A drive control module of the pump gathers voltage information, determines an improved pulse width based upon that voltage information, and then provides drive signals based upon the improved pulse width. Operating in this manner, a pump can operate at or near peak efficiency despite both significant variances in input voltage and non-sinusoidal input voltage, and without customized components or adapters.

Systems and methods are disclosed of monitoring performance of an incompressible fluid system. The system has a positive displacement pump and a high bandwidth pressure sensor. A method comprises sensing a pressure of the fluid with the pressure sensor, determining pump ripple frequency and hence the speed of the positive displacement pump, calculating the pump flow rate, determining a flow restriction of the fluid system based on the pressure and flow, and assessing or trending the fluid system flow restriction.

A compressor having a front housing in which a crank chamber is formed. A cylinder block is coupled to an opposite surface facing the front housing and includes reciprocating pistons in a plurality of cylinder bores. A rear housing is coupled to an opposite surface facing the cylinder block, the rear housing includes a suction chamber and a discharge chamber formed therein. A rotating shaft 400 is inserted via centers of the front housing and the cylinder block, the shaft inserted into a swash plate. A diameter maintenance part is configured to constantly maintain a diameter based on an axis direction of the piston 220. A sensor part is configured to sense a speed and a stroke of the piston in accordance with a change in position of a position determination part positioned on one side of the diameter maintenance part.

A method of probabilistically estimating a velocity of a plunger of a beam pump may comprise continuously monitoring well acoustics using a plurality of passive acoustic sensors attached to external structures of the beam pump; digitizing outputs of the plurality of passive acoustic sensors and sending the digitized outputs to a computing device for storage and processing; and using the digitized outputs of the plurality of passive acoustic sensors, estimating a probability of the velocity of the plunger using a hidden Markov model (HMM) to represent a probability of a position and the probability of the velocity of the plunger, the HMM comprising a state space model and an observational model.

A liquid feeding apparatus includes: a plurality of plunger pumps fluidly connected in series or in parallel between a suction flow path and a discharge flow path; and a control unit configured to control an operation of the plunger pump. The control unit includes a compensation flow rate calculation unit configured to calculate a positive compensation flow rate which changes with time in synchronization with the period with respect to a set flow rate. The compensation flow rate is a flow rate which compensates for a loss of the flow rate caused by cooling and contraction in a discharge stroke after the fluid in the plunger pump is compressed and heated in a pre-compression stroke. The compensation flow rate calculation unit is configured to calculate the compensation flow rate.

A controller for operating a rod pumping unit at a pump speed. The controller includes a processor configured to operate a pump piston of the rod pumping unit at a first speed. The processor is further configured to determine a pump fillage level for a pump stroke based on a position signal and a load signal. The processor is further configured to reduce the pump speed to a second speed based on the pump fillage level for the pump stroke.

Devices and methods for operating a diaphragm compressor system provide high output pressure and high throughput. In some embodiments, modular diaphragm compressors are stacked with a clamping mechanism pressing the compressor modules together. In embodiments, multiple stacks are provided as stages of a pressurization process. In embodiments, a main stage valve controls one or more pressure circuits for one or more hydraulic actuators of compressor modules. In embodiments, orifices configured for damping are incorporated to control actuator piston movement within a compressor module.

A variable speed drive for use in connection with a beam pumping unit has a pair of DC bus rails that include a positive DC bus rail and a negative DC bus rail. The variable speed drive further comprises a rectifier section, an inverter section connected between the DC bus rails and a primary capacitor bank. The primary capacitor bank includes a primary capacitor and an overvoltage switch. The variable speed drive further includes an auxiliary capacitor bank that has an auxiliary capacitor, a charge diode connected between the auxiliary capacitor and the overvoltage switch, and a discharge diode connected between the auxiliary capacitor and the positive DC bus rail.

The liquid feeding device includes a discharge speed calculation part configured to calculate a discharge speed v of the plunger pump so that a converted value L.sub.ATM under an atmospheric pressure of a flow rate L.sub.PRE of the mobile phase discharged to the discharge channel from the pump part becomes a set flow rate L.sub.SET using a volume V of the mobile phase in the pump chamber of the closing pump immediately before the precompression process is started, a volume V reduced due to the precompression process of the mobile phase in the pump chamber of the closing pump, and a feeding pressure P; and a discharge operation controller configured to control a discharge speed of the plunger pump to a discharge speed v calculated by the discharge speed calculation part.

A compressor having a front housing in which a crank chamber is formed. A cylinder block is coupled to an opposite surface facing the front housing and includes reciprocating pistons in a plurality of cylinder bores. A rear housing is coupled to an opposite surface facing the cylinder block, the rear housing includes a suction chamber and a discharge chamber formed therein. A rotating shaft 400 is inserted via centers of the front housing and the cylinder block, the shaft inserted into a swash plate. A diameter maintenance part is configured to constantly maintain a diameter based on an axis direction of the piston 220. A sensor part is configured to sense a speed and a stroke of the piston in accordance with a change in position of a position determination part positioned on one side of the diameter maintenance part.