Dual Fuel Injection Valve Hybrid Nozzle Sequential Control
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Solution Overview
Problem
Conventional diesel and gas engines face inefficiencies due to the need for separate fuel injection mechanisms and large sac volumes, leading to incomplete fuel injection and reduced combustion performance, especially when handling dual fuels like HFO and natural gas.
Innovation Solution
A dual fuel injection valve apparatus with a hybrid nozzle that uses pressure differences and spring tension to sequentially inject two types of fuel from a single valve, minimizing sac volume and allowing for efficient combustion of MDO+HFO and MDO+gas fuel combinations without mixing, thereby improving fuel efficiency and reducing harmful emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional diesel engine uses one needle valve and one spring with predefined opening pressure, then the fuel injection system is simple, but the injection is incomplete when pressure exceeds opening pressure and sac volume is large causing residue fuel to flow into cylinder
Solution Approach 1:
The fuel injection valve is segmented into two independent needle valves (first needle valve for pilot fuel, second needle valve for main fuel) with separate control mechanisms. This allows independent control of pilot injection and main injection, ensuring complete injection for each stage while maintaining manageable complexity through modular design
Solution Approach 2:
The first needle valve is nested within the second needle valve structure, with both valves sharing a common body and nozzle assembly. This nested configuration reduces overall structural complexity while enabling sequential injection - the inner pilot valve operates first, followed by the outer main valve, ensuring complete fuel delivery
2Adaptability or versatility
If a gas engine uses two fuel injection valves (one for pilot valve, one for main valve) with two fuel supply paths, then the dual fuel injection capability is achieved, but the device complexity increases requiring two governors and linkage devices
Solution Approach 1:
Two separate fuel injection valves are merged into a single integrated valve body containing both the first needle valve (pilot fuel) and second needle valve (main fuel). The common nozzle assembly and shared control linkage reduce the number of governors and control mechanisms from two to one, while maintaining full dual fuel injection capability
Solution Approach 2:
The single fuel injection valve body performs multiple functions: it houses both pilot fuel injection (first needle valve) and main fuel injection (second needle valve), controls both injection stages, and interfaces with a single governor mechanism. This multi-functional design achieves dual fuel capability without requiring separate control systems
3Device complexity
If Wartsila-Sulzer approach uses conventional fuel valve with pressure greater than opening pressure but fails to form high pressure, then the valve structure is simple, but fuel flows into cylinder rather than being injected through multiple nozzle holes
Solution Approach 1:
The injection system uses dynamic pressure staging with two sequentially operating needle valves. The first needle valve responds to lower pilot fuel pressure to initiate injection, while the second needle valve responds to higher main fuel pressure to complete injection. This dynamic sequential operation ensures precise fuel delivery across varying pressure conditions without requiring overly complex valve structures
4Volume of stationary object
If MAN-B & W approach uses needle valve in slide type to reduce sac volume, then the sac volume is minimized, but pressure above opening pressure cannot be actively coped with
Solution Approach 1:
The single slide-type needle valve is segmented into two independently controllable needle valves (first and second needle valves) with separate fuel supply paths. This segmentation maintains the compact sac volume design while adding pressure control versatility - each needle valve can be independently activated at different pressure thresholds, enabling active coping with varying pressure conditions above opening pressure
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 apparatus enables efficient injection and combustion of dual fuels, reducing emissions and improving fuel efficiency by minimizing sac volume and allowing for sequential fuel injection, thus enhancing combustion performance and simplifying engine configuration.
Implementation Method 1
a needle spring (60) connected to the main needle valve (50) through a spring support (61) and having an elastic force used in injection
Implementation Method 2
pressure difference between two fuel and opening pressure of the two fuel by using a spring on one valve axis in one valve
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The present invention relates to a dual fuel injection valve apparatus provided with a hybrid nozzle for a diesel engine and a gas engine and an objective thereof is to provide a dual fuel injection valve apparatus provided with a hybrid nozzle for a diesel engine and a gas engine, being capable of respectively injecting two kinds of different fuels from one fuel injection valve by pressure of fuel and tension of a spring. In a fuel injection valve apparatus for injecting fuel to a cylinder of a diesel engine or a gas engine, the present invention sequentially injects, without mixing, two kinds of fuel through respective nozzle holes by pressure of the two kinds of fuel introduced to a fuel valve and tension of a needle spring.