Fuel Consumption Measurement System with Segmented Return Lines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fuel consumption-measuring systems for internal combustion engines face inaccuracies due to large return fuel flows, which can be ten times or even hundred times the consumption, and pressure changes caused by pump regulation, leading to errors in engine management and potential damage.
Innovation Solution
A fuel consumption-measuring system with two separate fuel return lines and a heat exchanger, where equal volume flow devices in both lines ensure accurate measurement without maintaining constant pressure, allowing return flows through the flow meter and reducing external hydraulic volume, thus avoiding interference with engine performance and regulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single flow meter is arranged in the feed line with a pressure regulating relief valve and heat exchanger, then fuel consumption measurement accuracy is improved, but pressure changes caused by pump regulation still lead to errors in engine management and potential damage
Solution Approach 1:
The fuel return system is segmented into two separate return lines: a first fuel return line that branches at the consumer and opens into the feed line downstream of the flow meter, and a second fuel return line that branches from the feed line upstream of the flow meter and opens into the fuel tank. This segmentation isolates the measurement point from pressure fluctuations caused by pump regulation, eliminating measurement errors while maintaining engine management stability.
2Quantity of substance
If return flows are large (ten times or hundred times the consumption), then the closed circuit system operates, but measurement accuracy deteriorates due to very large volumes returned
Solution Approach 1:
The second fuel return line extracts a portion of the return flow directly from the feed line upstream of the flow meter and returns it to the fuel tank, bypassing the flow meter. This extraction of large return volumes away from the measurement point prevents measurement inaccuracies while still maintaining the closed circuit operation necessary for engine performance.
3Measurement precision
If a pressure reducer is arranged in the feed line to maintain constant pressure, then measurement accuracy is improved, but return flow towards the tank is prevented causing undesired pressure increase
Solution Approach 1:
Instead of using a static pressure reducer, the system dynamically manages pressure through the two return lines. The first return line allows pressure regulation downstream of the flow meter, while the second return line provides an upstream pressure relief path to the tank, enabling adaptive pressure management that maintains measurement accuracy without causing pressure buildup.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables precise, temporally resolved fuel consumption measurement without influencing engine performance, accurately detecting return flows and maintaining consistent pressure, reducing errors from pressure variations and pulsations.
Implementation Method 1
a heat exchanger via which the fuel from the second fuel return line extracts heat from the fuel of the first fuel return line
Data Source
AI summary
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.