Diagnosis and controls of a fluid delivery apparatus with hydraulic buffer

摘要

A fluid delivery apparatus for delivering fluid according to a fluid delivery rate command including a fluid tank, a pump, a buffer, in which a pressure sensor is positioned, an injector, a pump controller, a fluid delivery controller, and a diagnostic controller. When a motor driven pump is used, the diagnostic controller is able to detect issues by comparing a measured pressure change with an expected value calculated using pressure sensing values and the power applied to the motor. If an air driven pump is employed, pressure sensing values, fluid delivery rate commands, and pump operating status can be used for calculating compressed air volume in the pump and trapped air volume in the buffer, and for further triggering pressing and suction strokes of the air driven pump, diagnosing issues in the fluid delivery apparatus, detecting fluid level in the fluid tank, and refilling trapped air in the buffer.

主权项

1. A fluid delivery apparatus with a diagnostic system, comprising:
a pump driving fluid into a buffer which is fluidly coupled to said pump; a pressure sensor providing a sensing signal indicative of a fluid pressure in said buffer; a nozzle fluidly coupled to said buffer for releasing fluid; a fluid delivery controller for controlling a fluid delivery rate configured to open and close said nozzle in response to a fluid delivery rate command; and a diagnostic controller for determining anomaly of said fluid delivery apparatus configured to calculate a pressure difference value with a first pressure sensing value obtained from said sensing signal at a first moment and a second pressure sensing value obtained from said sensing signal at a second moment, and calculate a total fluid delivery amount in between said first moment and said second moment with said fluid delivery rate command, and further configured to calculate an expected pressure change value according to at least said total fluid delivery amount and determine whether a difference between said pressure difference value and said expected pressure change value is within a predetermined range.