Fuel consumption-measuring system and method for measuring the fuel consumption of an internal combustion engine

Patent metadata

Field	Value
Publication number	US-10094345-B2
Application number	US-201515328062-A
Country	US
Kind code	B2
Filing date	Jul 24, 2015
Priority date	Jul 24, 2014
Publication date	Oct 9, 2018
Grant date	Oct 9, 2018

Abstract

A fuel consumption-measuring system includes a feed line, a first pump which pumps fuel from a tank via the feed line to a consumer, a fuel consumption-measuring device in the feed line, a first return line which branches off at the consumer and opens into the feed line between the fuel consumption-measuring device and the consumer, a second return line which branches off from the feed line between the first pump and the fuel consumption-measuring device which opens into the tank, a branch which leads from the feed line into the second return line, a heat exchanger, and a flow device arranged in the first and second return lines. The flow device provides an equal volume flow at an opening of the first return line into the feed line and at the branch leading from the feed line into the second return line.

First claim

What is claimed is:

1. A fuel consumption-measuring system comprising:
a fuel feed line;
a first fuel pump configured to pump fuel from a fuel tank via the fuel feed line to a consumer; a fuel consumption-measuring device arranged in the fuel feed line;
a first fuel return line arranged to branch off at the consumer and to open into the fuel feed line at an opening between the fuel consumption-measuring device and the consumer;
a second fuel return line arranged to branch off from the fuel feed line between the first fuel pump and the fuel consumption-measuring device and to open into the fuel tank;
a branch arranged to lead from the fuel feed line into the second fuel return line;
a heat exchanger configured so that fuel from the second fuel return line extracts heat from the fuel of the first fuel return line; and
at least one equal volume flow device arranged in the first fuel return line and in the second fuel return line, the at least one equal volume flow device being configured to provide an equal volume flow at the opening of the first fuel return line into the fuel feed line and at the branch leading from the fuel feed line into the second fuel return line; and
a volume flow regulating unit;
wherein,
a first flow meter is arranged in the first fuel return line as the at least one equal volume flow device to provide the equal volume flow from the first fuel return line into the fuel feed line,
a second flow meter is arranged in the second fuel return line as the at least one equal volume flow device to provide the equal volume flow from the fuel feed line into the second fuel return line, and
both the first flow meter and the second flow meter are electrically connected to the volume flow regulating unit.

2. The fuel consumption-measuring system as recited in claim 1 ,
wherein, the volume flow regulating unit is connected to the first flow meter and to the second flow meter, a regulating valve is arranged in the second fuel return line as the at least one equal volume flow device to provide the equal volume flow in the first fuel return line and in the second fuel return line, and the regulating valve is configured to be controlled via the volume flow regulating unit.

3. The fuel consumption-measuring system as recited in claim 2 , further comprising a second fuel pump arranged in the first fuel return line.

4. The fuel consumption-measuring system as recited in claim 3 , further comprising:
a pressure pickup arranged in the first fuel return line upstream of the heat exchanger; and
a pressure regulating unit which is electrically connected to the pressure pickup and to the second fuel pump.

5. The fuel consumption-measuring system as recited in claim 3 , further comprising:
a regulating valve,
wherein,
the regulating valve and the first flow meter are connected to the pressure regulating unit, and
the second fuel pump is configured to be operated at a constant rotational speed and is connected with the regulating valve in a circuit.

6. The fuel consumption-measuring system as recited in claim 5 , further comprising:
a circuit line arranged to branch from the fuel return line downstream of the heat exchanger and to open into the fuel return line downstream of the flow meter and upstream of the fuel pump,
wherein,
the second fuel pump is further arranged upstream of the heat exchanger, and
the regulating valve is arranged in the circuit line.

7. The fuel consumption-measuring system as recited in claim 3 , wherein,
the first flow meter and the second fuel pump are arranged downstream of the heat exchanger in the first fuel return line, and
the second flow meter and the regulating valve are arranged upstream of the heat exchanger in the second fuel return line.

8. The fuel consumption-measuring system as recited in claim 5 , wherein the second flow meter is arranged downstream of the heat exchanger in the second fuel return line.

9. The fuel consumption-measuring system as recited in claim 1 , further comprising:
a rotational displacer arranged in the fuel consumption-measuring device;
a bypass line arranged to bypass the rotational displacer;
a measuring chamber formed in the bypass line; and
a piston arranged in the bypass line,
wherein, the rotational displacer is configured to be driven as a function of a displacement of the piston.

10. The fuel consumption-measuring system as recited in claim 1 , further comprising:
a bypass valve arranged in the first fuel return line, the bypass valve being configured to guide fuel from the first fuel return line to the fuel feed line or back to the tank.

11. A method for measuring a fuel consumption of an internal combustion engine with the fuel consumption-measuring system as recited in claim 3 , the method comprising:
feeding the fuel from the tank to the consumer via the first fuel pump;
measuring a volume flow of the fuel fed via the fuel consumption-measuring device; and, during the measuring,
regulating to equal measuring values a volume flow in the first fuel return line, via which fuel flows from the consumer back to the fuel feed line between the consumer and the fuel consumption-measuring device, and in the second fuel return line via which fuel is fed from the fuel feed line back to the tank.

12. The method for measuring the fuel consumption of an internal combustion engine as recited in claim 11 , further comprising:
cooling down a temperature of the fuel in the first fuel return line upstream of the opening into the fuel feed line to be substantially a temperature of the fuel in the tank by using a heated fuel in the first fuel return line and a not-heated fuel in the second fuel return line as heat exchange media of the heat exchanger.

13. The method for measuring the fuel consumption of an internal combustion engine as recited in claim 11 , further comprising:
measuring a pressure of the fuel in the first fuel return line via a pressure pickup arranged in the first fuel return line upstream of the heat exchanger; and
regulating the second fuel pump downstream of the heat exchanger and upstream of the opening of the first fuel return line via a pressure regulating unit so that a constant pressure prevails in the first fuel return line.

14. The method for measuring the fuel consumption of an internal combustion engine as recited in claim 11 , further comprising:
regulating a pressure of the fuel in the first fuel return line via a regulating valve arranged in a circuit line, via the second fuel pump, and via a pressure regulating unit so that a constant pressure prevails in the region of the opening of the first fuel return line,
wherein, the circuit line is arranged to branch from the fuel return line downstream of the heat exchanger and to open into the fuel return line downstream of the flow meter and upstream of the fuel pump.

15. The method for measuring the fuel consumption of an internal combustion engine as recited in claim 11 , wherein,
the measuring of the volume flow of the fuel in the first fuel return line is measured by the first flow meter,
the volume flow of the fuel in the second fuel return line is measured by the second flow meter, and
the regulating to equal measuring values of the volume flow in the first return line and in the second fuel return line is performed by regulating the regulating valve in the second flow return line by the volume flow regulating unit.

16. The method for measuring the fuel consumption of an internal combustion engine as recited in claim 11 , further comprising:
when the measuring is not performed, returning a fuel flow f

Assignees

• Avl List Gmbh

Inventors

• Duerrwaechter Martin
• Tauch Michael
• Buchner Michael

Classifications

• G01F9/001

  with electric, electro-mechanic or electronic means (G01F9/008 and G01F9/02 take precedence) · CPC title

• F02M37/0023

  Valves in the fuel supply and return system · CPC title

• F02M31/20

  for cooling ({F02M31/005 takes precedence; use of cold F02M17/52;} cooling of charging-air or of scavenging-air F02B29/04) · CPC title

• F02M37/045

  Arrangements for driving rotary positive-displacement pumps · CPC title

• F02M37/0047 Primary

  Layout or arrangement of systems for feeding fuel (fuel injection apparatus characterised by their conduits and venting means F02M55/00; fuel injection apparatus having a common rail F02M63/0225; arrangement of fuel conduits of low pressure fuel injection apparatus F02M69/462) · CPC title