Gas Engine Priming System for Fast Startup

Solution Overview

Problem

Gaseous fuel powered engines, such as those used in gensets, require a longer time to start compared to diesel fuel engines due to the need for gaseous fuel to traverse a substantial portion of the intake system before reaching the combustion chamber, which is problematic for applications requiring rapid startup and compliance with regulatory standards.

Innovation Solution

A priming system that includes a throttle valve, an auxiliary fuel line, and a controller to direct fuel from a fuel source directly to a subset of cylinders, allowing for quicker engine startup by bypassing the compressor and throttle valve, and ceasing fuel delivery when the engine parameter exceeds a threshold, ensuring efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If gaseous fuel is supplied through the intake system upstream of the compressor, then the fuel can be delivered to the combustion chamber, but the engine startup time increases significantly

Engineering Contradiction:

Improvefuel delivery reliabilityVSAvoidengine startup time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The fuel delivery system is segmented into two separate pathways: the original intake system pathway and a new direct priming pathway. The priming system includes a priming fuel line that connects the fuel source directly to the combustion chamber, bypassing the compressor and intake manifold. This segmentation allows fuel to reach the combustion chamber through two different routes, with the direct route used during startup and the normal route used during operation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The priming function is extracted from the main fuel delivery system. A separate priming system is created with its own fuel line, valve, and control mechanism that is independent from the normal intake system. This extracted priming system can operate autonomously during startup without interfering with the normal fuel delivery pathway, allowing for rapid fuel delivery to the combustion chamber.

Inventive Principle:

Principle #2Taking out (Extraction)

2Reliability

If a dual fuel source system with high-pressure and low-pressure sources is used, then the starting ability is improved, but the system complexity increases and requires replenishment of high-pressure fuel source

Engineering Contradiction:

Improvestarting abilityVSAvoidfuel source system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The priming function is extracted from the main fuel delivery system. A separate priming system is created with its own fuel line, valve, and control mechanism that is independent from the normal intake system. This extracted priming system can operate autonomously during startup without interfering with the normal fuel delivery pathway, allowing for rapid fuel delivery to the combustion chamber.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

An auxiliary fuel valve is introduced as an intermediary component to control the priming fuel line. This valve acts as a mediator between the fuel source and the combustion chamber during startup, allowing precise control of fuel delivery. The auxiliary fuel valve opens to allow priming fuel flow and closes when the engine reaches operational speed, seamlessly transitioning between priming mode and normal operation mode.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Loss of time

If fuel is directed directly to cylinders for rapid startup, then the startup time is reduced, but the normal fuel delivery pathway may be disrupted

Engineering Contradiction:

Improvestartup timeVSAvoidnormal operation reliability

Core Design Contradiction:

Loss of timeVSReliability

Solution Approach 1:

The fuel delivery system is segmented into two separate pathways: the original intake system pathway and a new direct priming pathway. The priming system includes a priming fuel line that connects the fuel source directly to the combustion chamber, bypassing the compressor and intake manifold. This segmentation allows fuel to reach the combustion chamber through two different routes, with the direct route used during startup and the normal route used during operation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically switches between different fuel delivery pathways based on operational requirements. During startup, the auxiliary fuel valve opens to enable the direct priming pathway, allowing rapid fuel delivery. When the engine reaches operational speed, the auxiliary fuel valve closes to disengage the priming system and activate the normal intake system pathway. This dynamic switching ensures optimal performance for each operational phase without disrupting normal operation.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS10502146B2Gas engine fast start fuel strategy

Publication Date: 2019.12.10 CATERPILLAR INC

AI summary

A priming system for an engine system having a throttle valve configured to regulate a flow of air and fuel into an intake manifold of an engine is disclosed. The priming system may include a first sensor configured to generate a first sensor signal indicative of a value of an engine parameter, an auxiliary fuel line configured to direct fuel from a fuel source to a primed cylinder subset of the plurality of cylinders, an auxiliary fuel valve disposed in the auxiliary fuel line, and a controller in communication with the first sensor and the auxiliary fuel valve. The controller may be configured determine the value of the engine parameter from the first sensor signal and cease directing fuel from the auxiliary fuel line to the primed cylinder subset when the engine parameter value is greater than or equal to a threshold engine parameter value.