Diesel Engine Predetermined Breaking Point for Overpressure Protection
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Solution Overview
Problem
Large two-stroke diesel engines are prone to severe damage and safety risks due to overpressure in the combustion chamber, which conventional safety valves cannot reliably prevent, leading to costly repairs and potential harm to operating personnel.
Innovation Solution
Incorporating a predetermined breaking point with a defined breaking pressure in the engine's outer wall, connected to an emergency blow-off duct that directs escaping gases and fragments to a safe collection environment, thereby preventing destructive overpressure and allowing for controlled pressure release.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional safety valves are used to prevent overpressure damage, then warning of impending cylinder head lifting is provided, but the safety valves work too slowly and cannot reliably prevent damage
Solution Approach 1:
The predetermined breaking point is pre-configured with a specific breaking pressure value that is lower than the damage threshold pressure. When overpressure occurs, the breaking point automatically breaks at the predetermined pressure level, releasing pressure before damage can occur. This preliminary configuration ensures both reliability and speed of pressure release without requiring slow-acting conventional safety valves.
2Speed
If a bursting disc is used to provide fast pressure release, then overpressure protection speed is improved, but the breaking pressure may not be precisely controlled below the damage threshold
Solution Approach 1:
The breaking pressure parameter of the predetermined breaking point is precisely controlled and configured to be below the damage threshold pressure but above normal operating pressure. This parameter optimization ensures that the breaking point activates at the correct pressure level, providing both fast response and precise pressure control to prevent overpressure damage.
3Reliability
If the predetermined breaking point breaks to release pressure, then overpressure damage is prevented, but fragments and hot gases are released into the environment
Solution Approach 1:
A receiving environment is introduced as an intermediary between the breaking point and the external environment. When the predetermined breaking point breaks, fragments and hot gases are directed into this receiving environment (such as a water-filled chamber or controlled containment space) rather than being released directly into the surrounding area. This intermediary structure captures and neutralizes the harmful effects while maintaining the overpressure protection function.
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 effectively prevents damage from overpressure by allowing a controlled release of gases and fragments, reducing the risk of engine damage and maintenance costs while ensuring safety, and can be designed for various engine operating conditions.
Implementation Method 1
overpressure occurring in the combustion chamber
Implementation Method 2
controlled release of gases and fragments
Data Source
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AI summary
The invention relates to a diesel engine, particularly a two-stroke crosshead large diesel engine, comprising at least one combustion chamber (1), which is enclosed by a cylinder on multiple sides and by at least one upper side of at least one piston moving up and down in the cylinder, which form an outer wall (3; 103) for the combustion chamber (1), wherein the combustion chamber (1) comprises a predetermined breaking point (12) on the outer wall (3; 103) thereof. The invention is characterized in that the predetermined breaking point (12) is suited to protect the diesel engine against possible damage that can be caused by an undesirably high overpressure (py) of gases in the combustion chamber (1) during a malfunction of the diesel engine, wherein the predetermined breaking point (12) has a breaking point pressure (ps) below the overpressure (py) above which damages can be expected, and above a combustion chamber normal pressure (pn) provided at a maximum during normal engine operation conditions. The invention further relates to a predetermined breaking point component and to a method, wherein in order to prevent the damage, at least one predetermined breaking point component of said kind is provided in the outer wall of at least one combustion chamber and/or the diesel engine is designed according to the invention.