Patent Application
20230021491
The present disclosure relates to a method of controlling a positive displacement pump, and specifically to controlling a pump using a pressure differential.
Positive displacement pumps produce large parasitic losses in air breathing engine fluid systems. Traditionally pumps are controlled based on their mechanical linkage to engine speed and are sized for to meet extreme conditions which are rarely reached or operated at. This leads to oversizing, which then requires other oversized components and unneeded flow capacity in the vast majority of operational conditions. This unneeded flow is a source of parasitic losses within an engine environment. While conventional design, operation, and sizing methods have generally been considered satisfactory for their intended purpose, there is still a need in the art for improved pump controls and sizing methods. The present disclosure provides a solution for this need.
A method of controlling a pump is disclosed. The method includes monitoring a supply pressure of a pump, monitoring an outlet pressure of the pump, and commanding a motor to drive the pump at a speed based on a comparison of the supply pressure and the outlet pressure of the pump, where the pump is a positive displacement pump and the motor is an electric motor. The method can include receiving an initial pressure command from an engine controller. Commanding the motor can include changing a speed of the motor in response to a change from the initial pressure command from the engine controller and/or a change in differential pressure between the supply pressure and the outlet pressure.
It is also considered that the monitored pressures can be sent as electrical signals directly to a motor controller to electrical and directly sent back to the motor controller command the motor to drive the pump. The method can also include actuating a stator vane of an aircraft based on an increased or decreased pressure from the pump.
A system for operating the method described above is also disclosed. The system includes a motor, a pump operatively coupled to the motor to be driven by the motor, wherein the pump includes an input side and an output side, a pressure sensor to monitor a pressure difference between the input side and output side of the pump, and a motor controller to command the motor based on the detected pressure difference across the pump and monitor the pressure sensor. The motor controller can be operatively coupled to an engine controller, where the engine controller can be configured to provide a pressure command to the motor controller based on power required to accomplish an actuation task.
The pressure sensor can be configured to measure supply pressure and outlet pressure of the pump. The pressure sensor can include a first pressure sensing element located on a supply side of the pump, and a second pressure sensing element located on an output side of the pump. The pressure sensor can be a differential pressure sensor. It is also considered that the pressure sensor can include two independent sensors wherein each of the two independent sensors is configured to measure absolute pressure. The system can be part of an actuation system of an aircraft for actuating a stator vane or other air guiding element.
The motor controller used in the method includes non-transitory computer readable medium comprising computer executable instructions to execute the steps of the method described above. The motor controller can be configured to receive a pressure command from the engine controller to produce power required to accomplish an actuation task, wherein the engine controller can also be responsible for controlling an aircraft engine.
These and other features of the systems and methods of the subject disclosure will become more readily apparent to those skilled in the art from the following detailed description of the preferred embodiments taken in conjunction with the drawings.
So that those skilled in the art to which the subject disclosure appertains will readily understand how to make and use the devices and methods of the subject disclosure without undue experimentation, embodiments thereof will be described in detail herein below with reference to certain figures, wherein:
Reference will now be made to the drawings wherein like reference numerals identify similar structural features or aspects of the subject disclosure. For purposes of explanation and illustration, and not limitation, a schematic view of an exemplary embodiment of a system for controlling a pump based on a pressure difference between an input and output pressure on the pump in accordance with the disclosure is shown in
Referring now to
A pressure sensor having a pair of sensing elements 106a, 106b is used to monitor the pressure difference across pump 104. One pressure sensing element 106a is located on an input side 105 of pump 104 to sense input pressure of the pump 104. A second pressure sensing element 106b is located on an output side 107 of the pump 104 in order to sense output pressure from the pump 104. This type of pressure sensor can be a differential pressure sensor spanning a pump membrane in order to output a difference in pressures by referencing pressure with another location where pressure is also measure. It is also considered that each of the sensing elements 106a, 106b can be independent pressure sensors to measure and produce absolute pressure readings. The sensors 106a/b can be separate pressure transducers, each connected to the microcontroller 108 to monitor a pressure difference across the pump 104. Each one of the pressures sensing elements at each of the locations shown in
The motor controller 108 includes a non-transitory computer readable medium which includes computer executable instructions to monitor a supply pressure of the pump 104, monitor an outlet pressure of the pump 104, and monitor and control the speed of the electric motor 102 based on a comparison of the supply pressure and the outlet pressure of the pump.
The methods and systems of the present disclosure, as described above and shown in the drawings, provide for a method of designing and sizing an displacement pump system that is more attuned to the specific task it is required to perform. While the apparatus and methods of the subject disclosure have been shown and described with reference to preferred embodiments, those skilled in the art will readily appreciate that changes and/or modifications may be made thereto without departing from the scope of the subject disclosure.
