Dual-Loop EGR Cooling Device for Engine Exhaust Gas Recirculation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing cooling system for engine exhaust gas recirculation circuits, where the EGR exchanger and valve are integrated into a single cooling loop, leads to inefficiencies in heat dissipation, increased risk of fouling, and condensate formation, and excessive cooling that can hinder the effectiveness of catalytic converters.
Innovation Solution
A dual-loop cooling system is introduced, with a high-temperature loop for cooling the valve and a low-temperature loop for the EGR exchanger, using separate fluids and radiators to optimize heat dissipation and reduce fouling, while limiting EGR cooling to improve catalytic converter performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the EGR exchanger and valve are integrated into a single cooling loop, then the system structure is simplified, but heat dissipation efficiency deteriorates and fouling risk increases
Solution Approach 1:
The patent divides the cooling system into two separate loops: a high-temperature loop for the EGR exchanger and a low-temperature loop for the valve. This segmentation allows each component to be cooled at its optimal temperature, preventing condensation and fouling in the valve while maintaining effective heat dissipation in the exchanger, thus resolving the contradiction between structural simplicity and heat dissipation efficiency.
Solution Approach 2:
The patent applies different cooling temperatures to different parts of the system: the EGR exchanger is cooled at high temperature to maximize heat recovery, while the valve is cooled at low temperature to prevent condensation and fouling. This local differentiation of cooling quality optimizes both components' performance without requiring a complex integrated system.
2Temperature
If the valve is cooled extensively in a single loop, then valve temperature is reduced, but EGR cooling is excessive and catalytic converter effectiveness is hindered
Solution Approach 1:
By separating the cooling functions into two independent loops, the patent allows the valve to be cooled to appropriate temperatures without excessively cooling the EGR gas. The low-temperature loop supplies cooling only where needed (at the valve), while the high-temperature loop maintains EGR temperature for catalytic converter effectiveness, thus resolving the contradiction between valve temperature control and converter performance.
Solution Approach 2:
The patent introduces an intermediary thermal management approach where the EGR gas itself acts as a heat transfer medium in the high-temperature loop, allowing heat to be transferred from the exchanger to the cooling system without excessively cooling the gas that needs to reach the catalytic converter. This intermediary mechanism protects catalytic converter effectiveness while still enabling valve cooling.
3Device complexity
If a single cooling loop is used, then system complexity is reduced, but fouling and condensate formation at the valve increase
Solution Approach 1:
The patent applies local quality control by providing the valve with a dedicated low-temperature cooling loop that maintains the valve body at temperatures below the dew point of EGR, preventing condensation and fouling. Meanwhile, the EGR exchanger operates in a high-temperature loop that prevents condensate formation in the heat exchange surfaces, thus eliminating fouling issues without requiring overly complex system architecture.
Solution Approach 2:
The cooling system is designed to automatically maintain appropriate temperatures through the two-loop configuration, where the low-temperature loop continuously prevents condensation at the valve and the high-temperature loop prevents condensate formation in the exchanger. This self-regulating temperature control prevents fouling and condensate accumulation without requiring additional active control mechanisms.
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 dual-loop configuration enhances heat dissipation efficiency, reduces fouling and condensate formation, and optimizes EGR cooling, particularly during engine startup, thereby improving pollutant reduction and system reliability.
Implementation Method 1
a heat exchanger, known as an EGR exchanger, intended to allow an exchange of heat between the exhaust gases passing through said recirculation circuit and a cooling fluid
Implementation Method 2
an exchange of heat between the exhaust gases passing through said recirculation circuit and a cooling fluid
Implementation Method 3
an exchange of heat between the exhaust gases passing through said recirculation circuit and a cooling fluid
Implementation Method 4
each comprise a heat exchanger known respectively as a high-temperature and a low-temperature cooling radiator, allowing an exchange of heat between a stream of ambient air and, respectively, said first and second fluids
Implementation Method 5
allowing an exchange of heat between a stream of ambient air and, respectively, said first and second fluids
Implementation Method 6
allowing an exchange of heat between a stream of ambient air and, respectively, said first and second fluids
Implementation Method 7
the low-temperature loop comprises an intercooler, said intercooler allowing an exchange of heat between the air that passes through an engine air supply circuit and the fluid of said low-temperature loop
Implementation Method 8
said intercooler allowing an exchange of heat between the air that passes through an engine air supply circuit and the fluid of said low-temperature loop
Implementation Method 9
said intercooler allowing an exchange of heat between the air that passes through an engine air supply circuit and the fluid of said low-temperature loop
Implementation Method 10
the high-temperature loop comprises a heating radiator, said loop being configured to allow an exchange of heat between air passing through said heating radiator and the first fluid leaving said valve cooling means
Implementation Method 11
allow an exchange of heat between air passing through said heating radiator and the first fluid leaving said valve cooling means
Implementation Method 12
allow an exchange of heat between air passing through said heating radiator and the first fluid leaving said valve cooling means
Data Source
AI summary
The invention relates to a cooling device for an engine (1) exhaust gas recirculation circuit, notably that of a motor vehicle, said circuit comprising a valve (2) for controlling the circulation of said gas, said device comprising a heat exchanger (3), known as the EGR exchanger, intended to allow an exchange of heat between the exhaust gases passing through said recirculation circuit and a coolant fluid, and means (4) of cooling said valve. According to the invention, said device comprises a cooling loop (5), known as a high-temperature cooling loop and configured so that said valve cooling means (4) have a first fluid passing through them, and a second cooling loop (12), known as a low-temperature cooling loop and configured so that the EGR exchanger (3) has passing through it a second fluid at a temperature lower than that of the first fluid. The invention also relates to an assembly of an exhaust gas recirculation circuit and of such a cooling device, and to a system for supplying an engine, notably a supercharged diesel engine, with charge gases and comprising an engine air supply circuit and such an assembly.