Multiple element firing strategy for cryogenic pump
AssigneeCaterpillar Inc.
InventorsJoshua W. Steffen, Sunil J. Bean
Life of this patent
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Abstract
A pump has a plurality of pumping elements, each being independently responsive to an actuation signal from a controller. The controller is programmed to maintain a desired pressure at the pump discharge, monitor the fluid pressure at the pump discharge, compare the fluid pressure with the desired fluid pressure to determine a pressure error, provide commands to sequentially actuate the pumping elements when the pressure error is within a threshold range, and provide commands to actuate more than one of the plurality of pumping elements simultaneously, such that more than one pumped amounts of fluid are delivered simultaneously at the pump discharge, when the pressure error droops outside of the threshold range.
Claims20
A fluid system, comprising:
- a pump having a plurality of pumping elements, each of the plurality of pumping elements being independently responsive to a corresponding actuation signal to perform a pumping stroke that delivers a pumped amount of fluid at a pump discharge;
- a pressure sensor disposed to monitor a fluid pressure at the pump discharge and provide a pressure signal;
- an electronic controller associated with the pump and the pressure sensor, the electronic controller disposed to receive the pressure signal and provide the corresponding actuation signal to each of the plurality of pumping elements, the electronic controller being further programmed to maintain a desired pressure at the pump discharge, the electronic controller being programmed to:
- monitor the fluid pressure provided by the pressure sensor;
- compare the fluid pressure with the desired pressure to determine a pressure error;
- provide commands to sequentially actuate the plurality of pumping elements when the pressure error is within a threshold range;
- and
- provide commands to actuate more than one of the plurality of pumping elements simultaneously, such that more than one pumped amounts of fluid are delivered simultaneously at the pump discharge, when the pressure error droops outside of the threshold range.
A method for operating a pump, comprising:
- providing a plurality of pumping elements, each being independently actuated in response to an actuation signal from a controller;
- receiving and monitoring at the controller a plurality of engine operating parameters including a pressure signal that is directly or indirectly indicative of a pump discharge pressure at a pump discharge;
- comparing the pump discharge pressure with a desired discharge pressure;
- providing a command to sequentially actuate pumping elements at a desired frequency;
- determining whether the pump is capable of providing a desired pressure within a desired time;
- and
- providing a command to non-sequentially actuate more than one pumping element simultaneously when an indication is present that sequential pumping element actuations will be insufficient to achieve the desired discharge pressure of the pump.
A fuel system for an engine, comprising:
- a cryogenic fluid storage tank containing a fuel;
- a pump having a plurality of pumping elements, each of the plurality of pumping elements being independently responsive to a corresponding actuation signal to perform a pumping stroke that delivers a pumped amount of fuel at a pump discharge;
- a pressure sensor disposed to monitor a fluid pressure at the pump discharge and provide a pressure signal;
- an electronic controller associated with the pump and the pressure sensor, the electronic controller disposed to receive the pressure signal and provide the corresponding actuation signal to each of the plurality of pumping elements, the electronic controller being further programmed to maintain a desired pressure at the pump discharge, the electronic controller being programmed to:
- monitor the fluid pressure provided by the pressure sensor;
- compare the fluid pressure with the desired pressure to determine a pressure error;
- provide commands to sequentially actuate the plurality of pumping elements when the pressure error is within a threshold range;
- and
- provide commands to actuate more than one of the plurality of pumping elements simultaneously, such that more than one pumped amounts of fluid are delivered simultaneously at the pump discharge, when the pressure error droops outside of the threshold range.
Dependencies are inferred from the claim text.