Engine Control Method for Accelerating Coolant Temperature Rise
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Solution Overview
Problem
Existing methods for accelerating the temperature rise of a combustion engine's coolant during cold starts are inefficient, often leading to overfuel consumption and ineffective operation of pollution control devices, as they rely on interrupting fuel injection, which cools the engine and prolongs the heating process.
Innovation Solution
Limiting the admission of fresh air into cylinders during deceleration while maintaining gaseous filling through exhaust recirculation, using existing engine control systems and components like the EGR valve and butterfly valve, to prevent coolant cooling and accelerate temperature rise without fuel overconsumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If fuel injection is interrupted during engine deceleration to reduce emissions, then exhaust emissions are reduced, but the engine is cooled by fresh air and the coolant temperature rise is slowed
Solution Approach 1:
The patent introduces exhaust gas recirculation as an intermediary substance to replace fresh air during deceleration. Instead of directly admitting cold fresh air into cylinders (which cools the engine), the system recirculates hot exhaust gases through the EGR valve to maintain cylinder filling while preventing engine cooling. This mediator (exhaust gas) transfers the filling function from fresh air to a thermally beneficial gas.
Solution Approach 2:
The patent changes the thermal parameter of the intake gas by recirculating hot exhaust gases instead of cold fresh air. The EGR valve controls the quantity of recirculated exhaust gas, thereby adjusting the temperature parameter of the gas entering the cylinders. This parameter change ensures that cylinder filling is maintained while preventing the engine and coolant from cooling during deceleration.
2Temperature
If fresh air admission is limited during deceleration to prevent engine cooling, then coolant temperature is maintained, but cylinder filling may be insufficient
Solution Approach 1:
Exhaust gas serves as an intermediary substance that fulfills the cylinder filling requirement without the harmful cooling effect of fresh air. The EGR valve regulates the amount of exhaust gas recirculated to match the filling requirements during deceleration, ensuring adequate cylinder filling while maintaining engine temperature.
Solution Approach 2:
The recirculated exhaust gas performs multiple functions simultaneously: it maintains cylinder filling during deceleration (replacing the filling function of fresh air) and prevents engine cooling (providing thermal benefit). This multi-functionality resolves the contradiction between maintaining filling and preventing temperature drop.
3Temperature
If exhaust gas recirculation is used to maintain cylinder filling during deceleration, then engine temperature is maintained, but pollution control device effectiveness may be reduced due to less fresh air
Solution Approach 1:
The patent applies partial exhaust gas recirculation during deceleration rather than complete fresh air cutoff. The EGR valve controls a regulated quantity of recirculated exhaust gas, providing just enough filling to prevent engine cooling while minimizing the impact on pollution control effectiveness. This partial action approach balances temperature maintenance with emission control.
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 quickly raises the coolant temperature, reduces fuel consumption, and enhances the effectiveness of pollution control devices by minimizing cold exhaust gas production and maintaining heat in the exhaust gas recirculation system, thereby accelerating engine and passenger compartment heating.
Implementation Method 1
equipped with an exhaust gas recirculation circuit (so-called EGR circuit, acronym for the English expression Exhaust Gas Recirculation)
Implementation Method 2
A heat engine such as an engine of a motor vehicle is cooled by means of a cooling liquid, such as water optionally added with glycol. This liquid circulates in a circuit passing through an air-cooled radiator
Implementation Method 3
when the engine decelerates, fuel injection is normally interrupted, so that the fresh air admitted into a combustion chamber is directly transferred to the exhaust. Since the combustion chamber is no longer heated by the combustion reaction
Data Source
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AI summary
The method involves applying strategy to accelerate rise in temperature of an engine during stopping of fuel injection and intaking fresh air in a cylinder while maintaining filling of the cylinder by reinjection of exhaust gas in an intake. The strategy is implemented on a set of engine cycles as engine temperature is below threshold temperature less than or equal to target temperature of engine operation.