Patent Publication Number: US-2007119514-A1

Title: Safety control system with electronic procedure of data acquisition for the inline-regulation of the max. permissible pressure during refueling of the aircraft

Description:
According to the international “Guidelines for Aviation Fuel Quality” from Jan. 9, 2004, by-pass-valves are necessary for airfield tank trucks with max. 1,000 liters/min. or more per hose.  
      The well-known inline-regulations for airfield tank trucks regulate the max. certified refueling pressure with the by-pass.  
      This procedure is uneconomical and leads to pressure loads in the armature system and at the hose end controller.  
      According to the international guidelines one person has to be positioned at the vehicle from where a clear overview to the control display devices such as differential pressure and by-pass is possible.  
      If one single person does the refueling difficulties exist to keep this regulation.  
      The aim of the invention is to automate the examinations and to use only the energy respectively number of revolutions of the pump of diesel engines which is necessary for the refueling of the aircraft.  
      This task is solved with an electronic safety control system of the speed adjusted feed pump. The acquired data of the received messages are sent to the already existing interface to the diesel drive engine. MAN interface for external control of number of revolutions—received messages A-CAN controlmodul STEP 1.  
      www.manted.de 
    
    
       FIG. 1  shows the diagram airfield tank truck. The resistance in the pressure conducting pipings and their armatures such as measuring instruments, filters and quantity counters is measured with the piston differential pressure gauge ( 9 ).  
      The piston in the glass cylinder is equipped with black and white fields ( 10 ). These fields are scanned with reflex light conductors, so that during the respective piston stroke movement of the horizontal fields a reflecting 1-signal respectively 0-signal is given.  
      With this binary code a data alignment of the velocity of flow is made for the calculation of the electronic control of number of revolutions.  
      For further calculation of the MAN received messages the data are determined by learning curves “pressure” at the hose ends.  
      For this determination of the learning curves there is a measuring connection for the pressure sensor X  1  and at the hose end a pressure measuring point X  2 , so that hereby due to the different hose resistances with the different velocities of flow the pressure at the hose end is determined.  
      Thus with 45 PSI pressure at the hose end the highest and with 35 PSI the economic driving speed of the feed pump is regulated.  
      In case of deviation of the normal differential pressure characteristic the refueling is interrupted automatically for safety reasons.  
      With this procedure the driving speed of the feed pump is raised when opening the tank valves in the aircraft and lowered when closing the tank valves, so that the max. refueling pressure cannot exceed 35 respectively 50 PSI.  
      By the audible change of the number of revolutions of the engine the regulation examines itself independently when refueling takes place.  
      Advantages  
     
         
         
           
              1. Cost saving by reduction and simplification of the armature systems. Fuel saving and less environment impact.  
              2. Reduction of personnel expenditure by saving of monitoring activities.  
              3. System control in the pressure conducting piping and their armatures as filtering, quantity counters and measuring instruments.  
              4. In case of leakages within the pressure range the refueling of the aircraft is interrupted automatically for safety reasons.  
              5. In case of the fact that one single person does the refueling of the aircraft the automatic control is particularly important.  
              6. In case of quality change the safety characteristic is left due to the changed density, so that the refueling of the aircraft is interrupted automatically. In this summary a substantial progress develops regarding the increase of safety of aircraft refueling.