Six-Stroke Internal Combustion Engine Waste Heat Recovery
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Solution Overview
Problem
Conventional internal combustion engines operate at low thermal efficiency, with a significant portion of heat energy being wasted as waste heat, which is not converted into useful work, leading to increased fuel consumption and cooling system requirements.
Innovation Solution
The engine operates in a six-stroke mode, where pressurized heated water and fuel are injected into the combustion chamber to form steam, which expands and drives an additional power stroke, capturing waste heat and reforming hydrocarbon fuel into hydrogen and carbon monoxide, increasing the heating value of the fuel and reducing cooling needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If water is injected into the cylinder after the exhaust stroke to be instantly turned to steam, then waste heat is captured and used to drive the piston for an additional power stroke, but the need for a cooling system remains and additional weight is required for water storage
Solution Approach 1:
The patent utilizes the phase transition of water from liquid to steam when injected into the hot combustion chamber. The water instantly vaporizes due to the high temperature, expanding and driving the piston for an additional power stroke. This phase transition enables waste heat recovery without requiring a separate cooling system, as the steam expansion process itself utilizes the thermal energy that would otherwise be wasted.
Solution Approach 2:
The patent converts the harmful waste heat expelled through the exhaust into a beneficial force by injecting water into the combustion chamber. The waste heat vaporizes the water, creating steam pressure that drives the piston for an additional power stroke. This transforms the previously harmful thermal energy loss into useful mechanical work, improving overall engine efficiency.
2Weight of moving object
If a cooling system is eliminated to reduce weight, then waste heat cannot be effectively managed, but adding a water tank for steam injection adds weight that offsets the cooling system weight reduction
Solution Approach 1:
The engine system performs its own cooling function through the steam injection process. The water injected into the combustion chamber absorbs waste heat and vaporizes, and the resulting steam is expelled through the exhaust system. This self-service mechanism eliminates the need for a separate cooling system, as the waste heat management is integrated into the power generation process itself.
Solution Approach 2:
The exhaust system serves dual functions: it continues to expel combustion products and now also serves as the pathway for steam expulsion. The water injection system simultaneously cools the combustion chamber and generates additional power through steam expansion. This multi-functionality eliminates the need for separate cooling and exhaust systems, reducing overall system weight.
3Use of energy by moving object
If pressurized water and fuel are injected into the combustion chamber for steam expansion, then thermal efficiency is improved, but the engine requires additional injection systems and control mechanisms
Solution Approach 1:
The patent merges the water injection system with the existing fuel injection system. Both water and fuel are injected through the same injection nozzle into the combustion chamber, utilizing the existing high-pressure fuel injection infrastructure. This integration reduces the need for separate water injection hardware and control systems, minimizing the increase in device complexity while achieving improved thermal efficiency.
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 approach enhances thermal efficiency by utilizing waste heat for steam expansion and fuel reforming, reducing cooling requirements and improving fuel consumption, while allowing the engine to operate in both six-stroke and four-stroke modes for various conditions.
Implementation Method 1
The catalyst body is heated to a temperature near or substantially equal to the temperature of the exhaust gas. During the fifth stroke, pressurized water and fuel is injected into the combustion chamber. The water, and alternatively also the fuel, is heated and is subsequently injected into the combustion chamber
Implementation Method 2
pressurized fuel and pressurized heated water is injected into the combustion chamber to be expanded. During the fifth stroke, pressurized water and fuel is injected into the combustion chamber. The water, and alternatively also the fuel, is heated and is subsequently injected into the combustion chamber to provide a relatively high cylinder pressure
Implementation Method 3
steam and gaseous fuel mixture is expelled through the catalyst body into a second exhaust conduit. reforming hydrocarbon fuel into hydrogen and carbon monoxide, increasing the heating value of the fuel
Data Source
AI summary
The disclosure relates to a method for operating an internal combustion engine in a six-stroke mode, wherein the engine comprises at least one cylinder with a reciprocating piston, each cylinder having at least one inlet and outlet valve. The method involves performing a first stroke where a gas comprising at least air is induced into a combustion chamber from an intake conduit; a second stroke where the gas and injected fuel is compressed; a third stroke where the compressed fuel/gas mixture is expanded following an ignition; a fourth stroke where combusted exhaust gas is expelled through a catalyst body into a first exhaust conduit; a fifth stroke where pressurized fuel and pressurized heated water is injected into the combustion chamber to be expanded; and a sixth stroke where steam and gaseous fuel mixture is expelled through the catalyst body into a second exhaust conduit.