Hydrogen Fuel Compressor-Expander for Injection Pressure Recovery
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Solution Overview
Problem
Hydrogen-fueled vehicles face inefficiencies in fuel delivery due to high energy requirements for compressing hydrogen from low tank pressures to high injection pressures, leading to reduced fuel capacity and fuel economy penalties, especially with direct injection systems.
Innovation Solution
Employing a compressor/expander system that operates in both compression and expansion modes, utilizing a piston-type device to manage fuel delivery pressure, recovering energy during expansion to offset fuel economy penalties and maintain efficient fuel delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If hydrogen fuel is stored at high pressure (700 bar) to increase fuel mass density and fuel range, then the fuel storage capacity is improved, but the energy required to compress the fuel during delivery increases significantly
Solution Approach 1:
The patent converts the harmful energy loss during fuel expansion into a beneficial energy source. When hydrogen fuel expands from high storage pressure to lower delivery pressure, the system captures the expansion energy through a turbine or expander device, transforming what would be wasted energy into useful work that offsets the compression energy required during fuel delivery.
Solution Approach 2:
The system dynamically changes the pressure parameters of hydrogen fuel delivery based on tank pressure levels. At high tank pressures, the system utilizes expansion energy recovery; at lower pressures, it switches to direct delivery or compressor-assisted delivery. This parameter adjustment optimizes the balance between compression energy input and expansion energy recovery throughout the fuel consumption cycle.
2Productivity
If direct injection systems are used to increase engine efficiency and performance, then engine performance is improved, but the minimum fuel tank pressure requirement increases to 300 bar, reducing usable fuel capacity
Solution Approach 1:
The system performs preliminary compression of hydrogen fuel to the required 300 bar injection pressure using a compressor driven by expansion energy recovery. This allows the fuel tank to maintain lower pressure (reducing the pressure differential and increasing usable fuel capacity) while still delivering fuel at the high pressure needed for direct injection engine performance.
Solution Approach 2:
The patent introduces an intermediary compression system between the fuel tank and the direct injection system. This intermediary compressor, powered by expansion energy recovery, bridges the gap between the lower tank pressure and the high injection pressure requirement, enabling both direct injection efficiency and increased usable fuel capacity.
3Stress or pressure
If fuel is delivered from low tank pressure to high injection pressure using conventional compression, then fuel delivery pressure is maintained, but fuel economy penalties increase due to high energy requirements
Solution Approach 1:
The system captures the harmful energy loss that occurs when high-pressure fuel expands to lower pressure in the delivery system by using a turbine or expander device. This expansion energy is converted into useful work to drive the compressor, transforming energy waste into a beneficial energy source that reduces the net energy penalty.
Solution Approach 2:
The patent merges the compression function and expansion energy recovery function into a single integrated system. The compressor and expander/turbine are coupled such that the expansion energy directly drives the compression process, creating a self-sustaining system that minimizes external energy input and reduces fuel economy penalties.
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
The system effectively recovers energy during high tank pressures, offsetting fuel economy penalties and increasing fuel range by minimizing throttling losses, allowing for efficient fuel delivery across varying tank pressures.
Implementation Method 1
a compressor/expander (13) installed in fluid communication with and between the fuel tank (12) and the engine's fuel delivery system
Implementation Method 2
Employing a compressor/expander system that operates in both compression and expansion modes, utilizing a piston-type device to manage fuel delivery pressure, recovering energy during expansion
Data Source
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AI summary
A fuel system for a vehicle having a fuel tank (12) for storing hydrogen fuel and an internal combustion engine (11). The internal combustion engine (11) has a fuel delivery system for injecting the hydrogen fuel into at least one combustion cylinder, comprising: a compressor/expander (13) in fluid connection between the fuel tank (12) and the engine's fuel delivery system, the compressor/expander (13) configured to: receive the hydrogen fuel from the fuel tank (12), deliver the hydrogen fuel at a desired fuel pressure to the fuel delivery system, operate in compressor mode when the hydrogen fuel in the fuel tank (12) is below the desired pressure, and operate in expander mode when the hydrogen fuel in the fuel tank (12) is above the desired pressure. The fuel delivery system further comprises a fuel tank pressure sensor (36) for measuring the pressure of the hydrogen fuel at the outlet of the fuel tank (12); a fuel tank temperature sensor (37) for measuring the temperature of the hydrogen fuel at the outlet of the fuel tank (12); an inlet metering valve (31) at the inlet to the compressor/expander (13) for metering flow timing and amount from the fuel tank (12) to the compressor/expander (13); an outlet metering valve (32) at the outlet from the compressor/expander (13) for metering flow timing and amount from the compressor /expander (13) to the fuel delivery system; and a controller (14) for receiving pressure and temperature measurements from the pressure sensor (36) and from the temperature sensor (37), for storing data representing the desired pressure, and for calculating timing of the opening and closing of the inlet metering valve (31) and the outlet metering valve (32) to maintain the desired pressure at a delivery point to the fuel delivery system.