Fuel Addition System Cold Start Temperature Control

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Solution Overview

Problem

Existing fuel addition systems require significant heat to raise the temperature of fuel injected into an exhaust passage for oxidation reduction reactions, which is inefficient, especially during cold starts when the internal combustion engine temperature is low.

Innovation Solution

A fuel addition system that includes a control device to detect fuel temperature and adjust the amount of fuel discharged through a pressure reduction valve to ensure the fuel reaches a reference temperature, using a pressure reduction fuel passage and check valves to maintain pressure and prevent backflow, thereby enhancing fuel temperature before injection into the exhaust passage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by stationary object

If low temperature fuel is injected from the fuel addition valve into the exhaust passage, then the fuel can be supplied without excessive heating, but the latent heat of vaporization causes the exhaust gas to fall in temperature and the exhaust purification catalyst to be cooled

Engineering Contradiction:

Improveheating energy for fuelVSAvoidexhaust gas temperature

Core Design Contradiction:

Use of energy by stationary objectVSTemperature

Solution Approach 1:

The system performs preliminary heating of fuel using engine coolant heat before injection. The fuel passage is positioned to allow heat exchange with coolant, and a heat insulating member prevents heat loss, so fuel is pre-heated to reduce vaporization heat demand and maintain exhaust temperature.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system converts the normally harmful cooling effect of fuel vaporization into a benefit by using the fuel's need for temperature increase as an opportunity to pre-heat it with coolant heat. The same vaporization process that would cool exhaust is instead used efficiently after pre-heating, reducing the net cooling impact.

Inventive Principle:

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

2Adaptability or versatility

If the temperature of the internal combustion engine is low during cold start, then the engine can start in cold conditions, but the fuel is not heated by the heat of the internal combustion engine

Engineering Contradiction:

Improvecold start capabilityVSAvoidfuel temperature

Core Design Contradiction:

Adaptability or versatilityVSTemperature

Solution Approach 1:

The system performs preliminary heating of fuel using coolant heat before injection. The fuel passage is positioned to allow heat exchange with coolant, and a heat insulating member prevents heat loss, so fuel is pre-heated to reduce vaporization heat demand and maintain exhaust temperature.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The coolant acts as an intermediary heat transfer medium. Heat from the coolant (which retains heat even during cold starts) is transferred to the fuel through the fuel passage, enabling fuel temperature increase without requiring high engine temperature.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 effectively increases the temperature of fuel injected into the exhaust passage, promoting oxidation reduction reactions without the need for excessive heating, even during cold starts, by optimizing fuel discharge and pressure management.

Implementation Method 1

a pressure reduction valve discharging fuel stored in the first pressure storage chamber to thereby lower the pressure of the first pressure storage chamber

Methodology Applied

Scientific EffectPressure reduction: Depressurisation

Implementation Method 2

the control device is configured to detect or estimate a temperature of fuel supplied to the fuel addition valve

Methodology Applied

Scientific EffectTemperature detection:

Implementation Method 3

controls an amount of fuel discharged from the first pressure storage chamber through the pressure reduction valve so that the temperature of the fuel becomes a reference temperature or more

Methodology Applied

Scientific EffectHeat transfer:

Data Source

PatentUS10443468B2Fuel addition system

Publication Date: 2019.10.15 SOKEN CO LTD

AI summary

The fuel addition system comprises: a fuel addition valve, a fuel tank, a first pressure storage chamber storing fuel to be supplied to a fuel injector, a supply pump increasing a pressure of fuel inside the fuel tank and supplying the fuel to the first pressure storage chamber, a pressure reduction valve discharging fuel stored in the first pressure storage chamber, a pressure reduction fuel passage supplying fuel discharged from the first pressure storage chamber to the fuel addition valve, and a control device controlling the fuel addition valve and the pressure reduction valve. The control device detects or estimates a temperature of fuel supplied to the fuel addition valve and, when injecting fuel from the fuel addition valve, controls an amount of fuel discharged from the first pressure storage chamber through the pressure reduction valve so that the temperature of the fuel becomes a reference temperature or more.