Direct-Injection Engine Water Injection Control Piston
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Direct-injection internal combustion engines face challenges in minimizing fuel consumption and reducing nitrogen oxide emissions, particularly due to thermodynamic disadvantages in low-temperature combustion methods and the sensitivity to water injection precision, as well as the costs and inefficiencies of exhaust gas aftertreatment systems.
Innovation Solution
A direct-injection supercharged internal combustion engine with a control piston mechanism that allows for precise water injection into the cylinder, using cylinder pressure to control the opening and closing of the fluid connection, ensuring defined water injection and durability, while being compatible with existing fuel injection systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If water is injected into the cylinder to reduce nitrogen oxide emissions and improve efficiency, then combustion temperature is lowered and fuel consumption is reduced, but precise control of water injection timing and quantity is required to avoid interfering with fuel spray and combustion
Solution Approach 1:
The patent combines the water injection system with the existing fuel injection nozzle, using the same injector body and mounting structure. The water injection device integrates a water supply line, control piston, and fluid connection within the nozzle holder, merging two injection functions into a single integrated component that shares mechanical structures and control systems.
Solution Approach 2:
The control piston is actuated by cylinder pressure through a fluid connection, creating a pressure-dependent feedback mechanism. The piston opens the water injection pathway when cylinder pressure exceeds a threshold value, automatically adjusting water injection timing based on real-time combustion conditions without requiring complex external sensing systems.
2Object-generated harmful factors
If a separate water injection system is implemented, then water can be injected into the cylinder, but the device complexity and cost increase
Solution Approach 1:
The water injection device is integrated into the existing fuel injection nozzle structure, sharing the nozzle holder, mounting threads, and overall architectural design. This merging approach allows water injection functionality to be added without requiring a completely separate injection system, thereby reducing device complexity and development costs.
Solution Approach 2:
The injection nozzle is designed to perform multiple functions: fuel injection, water injection, and potential future adaptations for other injectants. The universal nozzle body and holder structure can accommodate different injection media, making the system versatile and reducing the need for specialized components for each injection type.
3Object-generated harmful factors
If high exhaust-gas recirculation rates are used to reduce nitrogen oxide emissions, then combustion temperature is lowered, but the torque characteristics of the exhaust-gas turbocharger suffer due to reduced exhaust gas available for turbine driving
Solution Approach 1:
The invention changes the thermal parameters of the cylinder charge by injecting water, which has a high specific heat capacity and evaporation enthalpy. This directly lowers combustion temperature and reduces nitrogen oxide formation without requiring exhaust-gas recirculation, thereby maintaining exhaust gas flow and turbocharger performance while achieving the same emission reduction goal.
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 solution reduces nitrogen oxide emissions, improves engine efficiency, and maintains power output while minimizing fuel consumption, with the potential for retrofitting existing systems and reducing pollutant concentrations through comprehensive exhaust gas aftertreatment.
Implementation Method 1
closes at least one fluid connection in the inoperative position and opens up the at least one fluid connection in the working position in order to introduce water into the associated cylinder
Implementation Method 2
The water introduced into the fired cylinder is—like the fuel—heated and evaporated, and therefore the temperature of the gas mixture in the cylinder drops, in particular because of evaporation enthalpy. In addition, the volume of the water is considerably increased by means of the evaporation
Implementation Method 3
the temperature of the gas mixture in the cylinder drops, in particular because of evaporation enthalpy
Data Source
AI summary
Systems and methods are provided for a direct-injection engine having at least one cylinder head comprising at least one cylinder, in which each cylinder is assigned an injection nozzle which: is at least connectable to a fuel reservoir which serves for storing fuel, is secured in a nozzle holder, and is fitted with a nozzle needle which is displaceable in the direction of a longitudinal axis in a nozzle needle guide and, opens up at least one nozzle hole in order to introduce fuel. A control piston may be mounted movably on the injection nozzle, is displaceable in a translatory manner along the longitudinal axis of the injection nozzle between an inoperative position and a working position, and closes at least one fluid connection in the inoperative position and opens up same in the working position in order to introduce water into the associated cylinder.