Alcohol Reforming System with Buffer Tank for Engine Efficiency
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Solution Overview
Problem
The existing alcohol reforming systems for internal combustion engines face inefficiencies at high load conditions due to limited dilution tolerance and charge cooling of liquid ethanol, which reduces the effectiveness of reformate in improving engine efficiency.
Innovation Solution
An alcohol reforming system that includes a fuel system with a reformer and a buffer tank, where the alcohol-gasoline mixture is reformed into a reformate mixture comprising hydrogen gas and gasoline, with the buffer tank separating hydrogen gas from gasoline and re-introducing gasoline as a liquid into the fuel line, allowing for controlled delivery of reformate gas to the engine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If alcohol reforming is conducted at high load conditions, then the dilution tolerance provided by reformate is limited, but the charge cooling of liquid ethanol reduces the effectiveness of reformate in improving engine efficiency
Solution Approach 1:
The system segments the fuel delivery into two separate streams: a liquid fuel line delivering alcohol-gasoline mixture and a gaseous reformate line delivering reformed hydrogen-rich gas. This segmentation allows independent optimization of each fuel path, enabling the system to use liquid ethanol for charge cooling at high load while simultaneously injecting reformate to provide dilution tolerance, thereby resolving the contradiction between charge cooling loss and reformate effectiveness.
Solution Approach 2:
The reformate injection system provides multi-functionality by simultaneously addressing multiple engine requirements: it supplies hydrogen-rich gas for improved combustion efficiency, provides dilution tolerance for higher EGR rates, and complements the charge cooling effect of liquid ethanol. This universal solution allows the system to maintain high engine efficiency across varying load conditions despite the limitations of reformate alone.
2Reliability
If the reformer and subsystems provide a reliable supply of reformate, then the composition of the liquid fuel stream must be managed, but this increases system complexity
Solution Approach 1:
The system uses separate fuel delivery lines for liquid fuel and gaseous reformate, with independent control mechanisms for each. The liquid fuel line maintains proper alcohol-gasoline composition while the reformate line controls gaseous fuel injection. This segmentation simplifies composition management by decoupling the two fuel streams, allowing each to be optimized independently without increasing overall system complexity.
Solution Approach 2:
The system incorporates feedback control through oxygen sensors and engine control units that monitor exhaust composition and adjust reformate injection rates and liquid fuel composition in real-time. This feedback mechanism ensures reliable reformate supply while automatically managing fuel stream composition, thereby maintaining reliability without requiring complex manual intervention or overly complicated system architecture.
3Loss of energy
If reformate is used to enable dilute operation at part load, then throttling losses are reduced, but the system must manage the transition between part load and high load conditions
Solution Approach 1:
The system dynamically adjusts the mix of liquid fuel and gaseous reformate based on real-time engine load conditions. At part load, the system increases reformate injection to enable dilute operation and reduce throttling losses. At high load, it adjusts the composition to maintain proper charge cooling while providing supplemental hydrogen-rich gas. This dynamic adaptation allows the system to optimize performance across the entire operating range, resolving the contradiction between reducing throttling loss and maintaining load condition versatility.
Solution Approach 2:
The system changes key operating parameters including reformate injection rate, liquid fuel composition, and air-fuel ratio based on engine load conditions. These parameter changes enable the system to transition smoothly between part load and high load operation, maintaining optimal efficiency at each operating point while adapting to varying driving conditions.
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
This system enables efficient operation at part load conditions by providing a reliable supply of reformate, improving engine efficiency and reducing throttling losses, while managing the composition of the liquid fuel stream to prevent engine knock and maintain stable air-fuel ratios.
Implementation Method 1
A catalyst in the reformer catalyzes the transformation of the alcohol component of the fuel into a mixture of permanent gases
Implementation Method 2
CH3CH2OH→CH3CHO+H2 (1) CH3CHO→CH4+CO (2) CH3OH→CO+2H2 (3)
Implementation Method 3
the buffer tank configured to disengage the hydrogen gas from the gasoline in the reformate mixture
Implementation Method 4
The product is cooled by heat exchange and passes into a buffer tank
Data Source
AI summary
An alcohol reforming system for an internal combustion engine includes a reformer in selective fluid communication with a fuel line via a reformer inlet line for receiving liquid fuel from the fuel line. The reformer reforms the alcohol in the alcohol-gasoline mixture of the fuel into a reformate mixture comprising hydrogen gas and gasoline. A buffer tank in fluid communication with the reformer receives the reformate mixture and disengages the hydrogen gas from the gasoline in the reformate mixture. The buffer tank includes a liquid fuel outlet in fluid communication with the fuel line for re-introducing the gasoline as a liquid into the fuel line, and a reformate gas outlet for delivering the reformate gas to a reformate line through which the reformate gas is delivered to the engine.