Nested Bi-Fuel Tank Design for Emission Reduction

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Solution Overview

Problem

Existing bi-fuel vehicles require separate tanks for liquid and gas-phase fuels, leading to inefficiencies and increased emissions due to the need for separate storage and handling systems.

Innovation Solution

A dual fuel tank design where a pressurizable gas-phase fuel tank is entirely within the liquid fuel tank, allowing gas-phase fuel to permeate through the wall into the liquid fuel tank, where it is absorbed or dissolved, enhancing energy density and reducing emissions by maintaining low pressure in the ullage space through a liquid discriminating vent valve.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If separate tanks are used for liquid and gas-phase fuels, then storage and handling are simplified, but energy density and emissions performance deteriorate

Engineering Contradiction:
Improvetank structureVSAvoidenergy density
Core Design Contradiction:
Device complexityVSQuantity of substance

Solution Approach 1:

The gas-phase fuel tank is nested within the liquid fuel tank, with the gas tank positioned inside the liquid tank's interior space. This nested configuration allows both fuel types to be stored in a compact dual-tank arrangement that reduces overall vehicle space requirements while maintaining separate storage compartments, thereby improving energy density without significantly increasing device complexity

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent combines the storage functions of two separate fuel tanks into a integrated dual-tank system where the gas tank is housed within the liquid tank. This merging approach consolidates the fuel storage system, reducing the number of external components and improving energy density while the internal separation maintains functional simplicity

Inventive Principle:
Principle #5Merging (Combining)

2Device complexity

If separate tanks are used for liquid and gas-phase fuels, then storage is simplified, but hydrocarbon emissions increase

Engineering Contradiction:
Improvestorage systemVSAvoidhydrocarbon emissions
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The gas-phase fuel tank is nested within the liquid fuel tank, allowing hydrocarbons from the liquid fuel to act as a barrier and reduce evaporative emissions from the gas-phase fuel. This nested configuration enables the liquid fuel to suppress harmful emissions while maintaining simplified storage architecture

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent converts the potential harm of evaporative emissions from the gas-phase fuel into a benefit by allowing the liquid fuel to suppress these emissions. The liquid fuel acts as an emission control mechanism, transforming the storage configuration into an emission reduction strategy

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 design increases energy density per gallon of liquid fuel, reduces hydrocarbon emissions, and eliminates the need for an electric fuel pump, providing a cost-effective and efficient bi-fuel vehicle operation with reduced emissions.

Implementation Method 1

A gas-phase fuel is permeable through the wall. The pressurizable gas-phase fuel tank is to receive the gas-phase fuel, contain the gas-phase fuel, and supply the gas-phase fuel for combustion in the ICE

Methodology Applied
Scientific EffectPermeation: Permeation

Implementation Method 2

allowing gas-phase fuel to permeate through the wall into the liquid fuel tank, where it is absorbed or dissolved

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 3

allowing gas-phase fuel to permeate through the wall into the liquid fuel tank, where it is absorbed or dissolved

Methodology Applied
Scientific EffectDissolution: Solvation

Implementation Method 4

maintaining low pressure in the ullage space through a liquid discriminating vent valve

Methodology Applied
Scientific EffectVapor pressure: Vapour Pressure

Data Source

PatentUS9995260B2Bi-fuel vehicle
Publication Date: 2018.06.12 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A bi-fuel vehicle has an Internal Combustion Engine (ICE) to provide motive power to the vehicle by combustion of a liquid fuel and gas-phase fuel. The vehicle has a dual fuel tank including a liquid fuel tank to receive liquid fuel, contain the liquid fuel, and supply the liquid fuel for combustion in the ICE. The vehicle has a pressurizable gas-phase fuel tank defined by a wall. A gas-phase fuel is permeable through the wall. The pressurizable gas-phase fuel tank is to receive the gas-phase fuel, contain the gas-phase fuel, and supply the gas-phase fuel for combustion in the ICE. A shell envelops the pressurizable gas-phase fuel tank and defines an interior space of the liquid fuel tank. The wall is in fluid communication with the interior space. The interior space is to receive the permeated gas-phase fuel.