Fluid Accumulator Arrangement for Diesel Engine Pressure Control
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Solution Overview
Problem
Existing high pressure common rail designs for diesel engines face challenges in balancing volume and responsiveness to engine load changes, leading to compromises that affect combustion efficiency and system stability.
Innovation Solution
A fluid accumulator arrangement with two separable storage volumes connected by an electrically operated valve, allowing for variable volume control based on engine conditions, optimizing pressure management through control means that determine and compare pressure values to link or isolate the volumes accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the internal volume of the common rail is kept relatively small, then the high pressure fuel pump can change the fuel pressure in the common rail rapidly enough to maintain optimum combustion under abrupt load changes, but the fuel pressure becomes more responsive to injector filling events and less stable
Solution Approach 1:
The common rail is divided into a first common rail volume and a second accumulator volume that can be selectively connected or isolated. This segmentation allows the system to operate in different modes: when connected, the volumes provide a large total capacity for stability; when isolated, the first volume provides rapid pressure response for abrupt load changes.
Solution Approach 2:
The system dynamically adjusts the effective volume of the common rail by controlling the connection state between the first and second volumes based on engine operating conditions. The control system monitors load changes and injector filling events to determine when to connect or isolate the volumes, optimizing performance for each operating scenario.
2Stability of the object's composition
If a larger volume is used for the common rail, then the fuel pressure is more unresponsive to injector filling events providing greater stability, but the high pressure fuel pump cannot change the fuel pressure rapidly enough to maintain optimum combustion under abrupt load changes
Solution Approach 1:
The common rail is divided into a first common rail volume and a second accumulator volume that can be selectively connected or isolated. This segmentation allows the system to operate in different modes: when connected, the volumes provide a large total capacity for stability; when isolated, the first volume provides rapid pressure response for abrupt load changes.
Solution Approach 2:
The system dynamically adjusts the effective volume of the common rail by controlling the connection state between the first and second volumes based on engine operating conditions. The control system monitors load changes and injector filling events to determine when to connect or isolate the volumes, optimizing performance for each operating scenario.
3Stability of the object's composition
If the common rail volume is increased to reduce responsiveness to injector filling events, then fuel pressure stability improves, but the system complexity increases due to additional valve control mechanisms
Solution Approach 1:
The common rail is divided into a first common rail volume and a second accumulator volume that can be selectively connected or isolated. This segmentation allows the system to operate in different modes: when connected, the volumes provide a large total capacity for stability; when isolated, the first volume provides rapid pressure response for abrupt load changes.
Solution Approach 2:
The second volume serves multiple functions: it acts as an extension of the common rail when connected to increase total capacity and provide stability, and it can be isolated to allow the first volume to operate independently for rapid pressure response. The same structural element adapts its function based on the connection state controlled by the valve.
Data Source
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AI summary
A fluid accumulator arrangement suitable for use with a compression ignition internal- combustion engine comprising a first storage volume, a second storage volume, and valve means fluidly connected between the first storage volume and the second storage volume. In one embodiment, the valve means is a three-way control valve wherein, in a first position, the first storage volume communicates with the second storage volume, in a second position the first storage volume is isolated from the second storage volume and, in a third position, one of the first or second storage volumes communicates with a low pressure drain. The arrangement may also include control means to operate the valve means in accordance with predetermined control strategies.