A device for controlling a compressor of vehicles may include a sensor module including a cabin temperature sensor, an outdoor temperature sensor, an evaporator temperature sensor detecting a temperature of cooling medium in an evaporator, a vehicle speed sensor, and a brake sensor, an injector, an air conditioning system including a condenser, an evaporator, the compressor, a temperature control door controlling a temperature of air flowing into a cabin, an intake door selectively distributing an inner air or an outer air into the cabin, and a blower blowing the air to the intake door, and a controller controlling the injector and the air conditioning system, wherein the controller accumulates a cold air energy by increasing an operation of the compressor if a speed-reducing condition occurs, and the air conditioning system uses the accumulated cold air energy by decreasing the operation of the compressor if a release condition occurs.

An oscillation controller operates on engine speed or RPM data from a pump or pumping unit associated with a wellbore operation. The oscillation controller determines a measure of variability, such as a bandwidth, for the engine speed over a rolling time window and compares the measure of variability to an oscillation bandwidth threshold. The oscillation controller determines that erratic behavior or oscillation is present when the measure of variability exceeds the oscillation bandwidth threshold, and for such instances measures a duration of erratic behavior with a variability timer. If the oscillation controller determines that the erratic behavior has subsided, the variability timer is cleared. The oscillation controller generates at least one warning whenever the variability timer exceeds an oscillation warning threshold. The oscillation controller mitigates erratic behavior by downshifting (or shifting to neutral) at least one gear of the pump or pumping unit if the variability timer exceeds an oscillation mitigation time threshold.

A system according to the principles of the present disclosure includes a heat transfer rate module, a desired flow rate module, a flow rate adjustment module, and a pump control module. The heat transfer rate module determines a rate of heat transfer from an engine to coolant flowing through the engine based on a cylinder wall temperature and a measured coolant temperature. The desired flow rate module determines a desired rate of coolant flow through the engine based on the heat transfer rate. The flow rate adjustment module determines a coolant flow rate adjustment based on a desired coolant temperature and the measured coolant temperature. The pump control module controls a coolant pump to adjust an actual rate of coolant flow through the engine based on the desired coolant flow rate and the coolant flow rate adjustment.

A system according to the principles of the present disclosure includes a heat transfer rate module, a desired flow rate module, a flow rate adjustment module, and a pump control module. The heat transfer rate module determines a rate of heat transfer from an engine to coolant flowing through the engine based on a cylinder wall temperature and a measured coolant temperature. The desired flow rate module determines a desired rate of coolant flow through the engine based on the heat transfer rate. The flow rate adjustment module determines a coolant flow rate adjustment based on a desired coolant temperature and the measured coolant temperature. The pump control module controls a coolant pump to adjust an actual rate of coolant flow through the engine based on the desired coolant flow rate and the coolant flow rate adjustment.

A system includes a temperature estimation module and a pump control module. The temperature estimation module estimates a temperature of coolant flowing through an engine. The temperature estimation module estimates a temperature of a cylinder wall in the engine based on the estimated coolant temperature and a measured coolant temperature. The pump control module controls a coolant pump to adjust an actual rate of coolant flow through the engine based on the estimated cylinder wall temperature.

An example system includes a fluid end having a block, a fluid inlet formed in the block, and a fluid outlet formed in the block. The system also includes an intake manifold fluidly coupled to the fluid inlet, and a fluid conduit fluidly coupled to the fluid outlet and the intake manifold. The system further includes a valve fluidly coupled to the fluid conduit, the valve configured to control fluid flow through the fluid conduit, an actuator coupled to the valve and configured to position the valve in an open position or a closed position, and a controller communicatively coupled to the actuator and configured to send one or more signals to the actuator, causing the actuator to position the valve in the open position or the closed position.

Disclosed are parallel pumping controllers (e.g., control panels, etc.) with load sharing and systems including such parallel pumping controllers. An exemplary system includes first and second controllers. The first controller is configured for communication with a first engine for controlling operation of a first pump via the first engine. The second controller is configured for communication with the second engine for controlling operation of the second pump via the second engine. The first controller is further configured for communication with the second controller, whereby the first controller is operable for controlling operation of the first pump via the first engine and for controlling operation of the second pump via communications with the second controller, which responsively controls operation of the second engine according to the communications from the first controller.

An asphalt distributor has a multispeed hydraulic motor mechanically driving an asphalt pump. The asphalt distributor has a controller for controlling the flow rate of asphalt being sprayed. The controller has a gain for controlling the flow rate. During a transition when the speed of the multispeed hydraulic motor changes, the gain has a value for the transition. Beneficially, the asphalt distributor has a wider than conventional asphalt spraying flowrate over which it provides a consistent spray. A method for controlling the flowrate involves adjusting, preferably dynamically, the value of the gain during the transition.