Internal Combustion Engine Dual Compression Stroke Method
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Solution Overview
Problem
Internal combustion engines, particularly diesel engines, face inefficiencies when operating at part load or low load conditions, leading to poor combustion, unutilized fluid mediums, and increased pump losses, which result in reduced operational range and increased fuel consumption.
Innovation Solution
A method for operating an internal combustion engine that includes additional compression and work strokes, utilizing flow control valves to manage fluid medium flow, allowing for improved air utilization and reduced pressure in the cylinder, thereby enhancing engine efficiency and extending operational range to lower torque levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If the engine operates at part load or low load conditions, then the vehicle can maintain continuous operation, but combustion efficiency deteriorates and fuel consumption increases
Solution Approach 1:
The compression stroke is divided into two separate strokes: a first compression stroke that compresses air to a first pressure, and a second compression stroke that compresses the same air to a second pressure higher than the first. This segmentation allows the air to be compressed in stages, improving combustion efficiency at part load conditions while maintaining continuous operation.
Solution Approach 2:
The first compression stroke performs a preliminary compression of the air, raising it to a first pressure before the second compression stroke. This preliminary action prepares the air for more efficient combustion by establishing a baseline compression level, which is particularly beneficial for part load operation where full compression is not achieved in a single stroke.
2Duration of action of moving object
If the engine operates at part load or low load conditions, then the vehicle can maintain continuous operation, but pump losses increase
Solution Approach 1:
The compression process is segmented into two strokes with intermediate exhaust, allowing the piston to perform compression work in manageable increments rather than a single high-energy stroke. This reduces the peak power demands on the pump and improves overall energy efficiency during continuous operation at part load.
Solution Approach 2:
The method enables continuous operation by allowing the engine to complete multiple compression and power strokes without requiring full load conditions. The dual compression stroke system maintains useful work output while reducing energy losses, thereby extending continuous operation capability at efficient operating points.
3Duration of action of moving object
If the engine operates at part load or low load conditions, then the vehicle can maintain continuous operation, but air utilization decreases
Solution Approach 1:
The compression process is divided into two stages where air is compressed to a first pressure in the first stroke, then further compressed to a second pressure in the second stroke. This segmentation allows more thorough utilization of the incoming air by achieving higher compression ratios that improve combustion efficiency and air-fuel mixture utilization, thereby increasing air utilization at part load conditions.
4Device complexity
If conventional compression is used, then the engine structure remains simple, but operational range is limited
Solution Approach 1:
The compression stroke is segmented into two distinct strokes with a exhaust event between them. This segmentation enables the engine to achieve higher compression ratios and improved combustion efficiency without requiring a completely redesigned engine structure, thereby extending the operational range to include part load and low load conditions while maintaining relatively simple engine architecture.
Solution Approach 2:
The system dynamically adjusts the compression process by implementing two variable compression strokes with different pressure levels. This dynamic approach allows the engine to adapt to varying load conditions and extend operational range across different operating points without requiring multiple engine configurations or complex variable geometry components.
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 method improves engine efficiency at part load or low load conditions by increasing air utilization, reducing pump losses, and allowing continuous operation, which leads to smoother vehicle performance and reduced fuel consumption.
Implementation Method 1
any one of the inlet valves and the outlet valves comprises at least one flow control valve adapted to regulate the flow of a fluid medium passing through the flow control valve
Implementation Method 2
compressing the trapped fluid medium in a first compression stroke of the cylinder
Implementation Method 3
injecting a quantity of fuel into the cylinder and combusting the injected fuel
Implementation Method 4
performing a first work stroke to produce power to a crank shaft of the engine
Data Source
AI summary
The invention relates to a method (100) for operating an internal combustion engine (2), such as an internal combustion engine of a vehicle (1), the engine (2) comprising an engine cylinder (3) at least partly defining a combustion chamber (4) and a reciprocating piston (5), a number of inlet valves (20) in fluid communication with the combustion chamber and a number of exhaust valves (30) in fluid communication with the combustion chamber, wherein any one of the inlet valves and the outlet valves comprises at least one flow control valve. The method comprises the following steps: opening (105) at least one of the inlet valves and introducing the incoming fluid medium into the cylinder (3) of the engine by performing an intake stroke (S1); compressing (110) the trapped incoming fluid medium in a first compression stroke (CS1) of the cylinder (3), while having the number of the inlet valves and the number of the exhaust valves in a closed state; injecting (115) a quantity of fuel into the cylinder (3) and combusting said injected fuel; performing (120) a first work stroke (WS1) to produce power to a crank shaft of the engine, while controlling said flow control valve to partly exhaust burnt gases at the end of the work stroke; additionally compressing (125) remaining fluid medium in an additional compression stroke (CS2) of the cylinder (3), while having the number of the inlet valves and the number of the exhaust valves in a closed state; additionally injecting (130) an additional quantity of fuel into the cylinder (3); additionally performing (135) an additional work stroke (WS2) to produce power to the crank shaft of the engine, while controlling said flow control valve to partly exhaust burnt gases at the end of the additional work stroke; and opening (180) at least one of the exhaust valves and permitting partly burnt gases to expel from the cylinder via said at least one exhaust valve by performing an exhaust stroke (ES).