A pump device includes a first piezoelectric pump, a second piezoelectric pump connected in series to the first piezoelectric pump on an upstream side of the first piezoelectric pump, a driver unit that supplies alternating-current input power to the first piezoelectric pump and the second piezoelectric pump, and a distribution setting unit that sets a distribution ratio of the input power to be supplied from the driver unit to each of the first piezoelectric pump and the second piezoelectric pump, wherein the distribution setting unit sets a ratio of the input power for the second piezoelectric pump to the input power for the first piezoelectric pump to a value greater than 1 and equal to or less than 1.57.

A method of monitoring a low water volume of a water circulation system is disclosed that includes detecting an auxiliary measurement associated with an ancillary device fluidly coupled with a reservoir of water in a water circulation system and then determining whether the ancillary device is performing under a low water volume operation. The low water volume operation is based upon a comparison between at least the detected auxiliary measurement of the ancillary device and a condition associated with a performance of the ancillary device under the low water volume operation.

A control method and system for a resonant linear compressor applied for controlling the capacity of a cooling system. The method includes: a) reading a reference operation power (P.sub.ref) of the motor of the compressor; b) measuring an operation current (i.sub.MED); c) measuring an operation voltage of a control module of the compressor; d) calculating an input power (P.sub.MED) of the motor as a function of the operation current (i.sub.MED) and of the operation voltage; e) comparing the input power (P.sub.MED) with the reference operation power (P.sub.ref); f) if the reference operation power (P.sub.ref) is higher than the input power (P.sub.MED), then increase an operation voltage of the compressor (UC); g) if the reference operation power (P.sub.ref) is lower than the input power (P.sub.MED), then decrease the operation voltage of the compressor (UC).

A system and method for floodwater redistribution is disclosed. The system being comprised of onshore and offshore pump stations and pipelines deployed along the Gulf Coast to redistribute floodwaters to reservoirs located in the western United States. The pump stations include a network of controllers which monitor input/output head pressures and pump speeds and submit the data to the system server to determine the pump settings needed to optimize water flow along the line.

A pump device includes a first piezoelectric pump, a second piezoelectric pump connected in series to the first piezoelectric pump on an upstream side of the first piezoelectric pump, a driver unit that supplies alternating-current input power to the first piezoelectric pump and the second piezoelectric pump, and a distribution setting unit that sets a distribution ratio of the input power to be supplied from the driver unit to each of the first piezoelectric pump and the second piezoelectric pump, wherein the distribution setting unit sets a ratio of the input power for the second piezoelectric pump to the input power for the first piezoelectric pump to a value greater than 1 and equal to or less than 1.57.

An apparatus and a method may control a compressor. The apparatus may control a motor (included in a compressor) such that the motor quickly repeats turn-on and turn-off operations in a cooling power supply time period/section, thereby enabling the compressor to compress refrigerant in the cooling power supply time period/section. Thus, cooling power of a refrigerator may change while the compressor operates with maximum efficiency.

Systems, methods and apparatuses for monitoring the activity temperature controlled compartments of a refrigeration system by monitoring the activity of the compressor as the compressor changes between the ON or OFF state. In particular, the disclosure describes systems methods and tools for measuring the electrical loads drawn by the compressor for the purpose of predicting and determining the occurrence of unknown events from the energy profile of the compressors. One or more specialized computer systems may be connected between the compressor circuit and an energy source in order to monitor and track the amounts of energy being delivered to the compressor. The specialized computer systems measuring and tracking the electrical load supplied to the compressor may characterize the electrical load supplied as having one or more energy profiles. Each of the energy profiles may correspond to different types of events resulting in the consumption of energy by the compressor.

The present invention relates to a method for operating an undulating diaphragm pump comprising an undulating diaphragm and actuating means of the undulating diaphragm electrically powered according to a given frequency or voltage to make the undulating diaphragm oscillate and undulate. According to the invention, the method consists in modifying the electrical supply frequency and/or voltage of the actuating means according to at least one operating parameter, determined in advance, of the undulating diaphragm pump.

Methods and systems for monitoring a variable-speed pump system to detect a blockage condition. A value indicative of pump performance is sensed and a pump load coefficient is calculated. The value of the pump load coefficient does not change substantially due to changes in pump speed and is indicative of a blockage of a drain in a liquid holding tank. A blockage of the drain is detected based at least in part on the calculated pump load coefficient and the operation of the pump is adjusted based on the detected blockage.