Cooling System Controller Cold Start Flow Restriction
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Solution Overview
Problem
Existing cooling system controls for internal combustion engines with exhaust heat recovery systems fail to simultaneously shorten warm-up time and prevent coolant boiling, especially during cold starts.
Innovation Solution
A cooling system controller that restricts coolant flow rate during cold starts using a zero flow control strategy, which is released based on temperature thresholds for both the internal combustion engine and exhaust heat recovery system, ensuring efficient warm-up and preventing boiling through a combination of a water pump, multi-flow control valve, and exhaust heat recovery system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If coolant flow rate is restricted during cold start to shorten warm-up time, then warm-up time is reduced, but coolant boiling risk increases
Solution Approach 1:
The patent implements dynamic control of coolant flow rate through the EGR cooler based on real-time temperature conditions. During cold start, the control valve adjusts flow rate dynamically - restricting flow when engine coolant temperature is below the EGR cooler inlet temperature to prevent boiling, and increasing flow when temperature rises above the threshold. This dynamic adjustment resolves the contradiction by adapting flow rate to changing thermal conditions.
Solution Approach 2:
The control system continuously monitors engine coolant temperature and compares it with the EGR cooler inlet temperature to determine appropriate coolant flow rate. This feedback mechanism ensures that flow rate restrictions are applied only when necessary for preventing boiling, while automatically releasing restrictions when temperature conditions allow, thus shortening warm-up time without compromising boiling prevention.
2Reliability
If coolant flow rate is increased to prevent boiling in exhaust heat recovery system, then boiling prevention is improved, but warm-up time increases
Solution Approach 1:
The system dynamically adjusts coolant flow rate through the EGR cooler based on temperature differential between engine coolant and EGR cooler inlet. When engine coolant temperature is significantly lower than EGR cooler inlet temperature, flow rate is restricted to maintain temperature differential and prevent boiling. When temperatures converge, flow rate is increased to enhance cooling capacity, thus preventing boiling without unnecessarily extending warm-up time.
Solution Approach 2:
The control strategy changes the coolant flow rate parameter based on thermal conditions. By monitoring temperature differential and adjusting flow rate accordingly, the system optimizes the balance between preventing boiling in the EGR cooler and maintaining efficient engine warm-up, resolving the contradiction between these two requirements.
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 reduces warm-up time, stabilizes combustion, improves fuel efficiency, and prevents coolant boiling in both the internal combustion engine and exhaust heat recovery system, while leveraging exhaust heat for efficient heating operations.
Implementation Method 1
an exhaust heat recovery system configured to perform heat exchange from the exhaust gas of the internal combustion engine to the coolant
Implementation Method 2
a heat radiator configured to radiate heat from the coolant passing through the engine coolant passage to the external air to lower a temperature of the coolant
Data Source
AI summary
A cooling system controller controls a cooling system at least having a coolant pump (3) configured to supply a coolant to an internal combustion engine, a heat radiator (9) configured to cool the coolant, and an exhaust heat recovery system (6) configured to perform in heat exchange between the exhaust gas and the coolant. In addition, the cooling system controller (12) has a unit configured to control the coolant flow rate, a unit (13) configured to obtain a coolant temperature or pressure of the internal coolant passage of the engine, and a unit configured to obtain an internal coolant temperature or pressure of the exhaust heat recovery system. Furthermore, the coolant flow rate is restricted at a cold start of the internal combustion engine, and the restriction of the coolant flow rate is released on the basis of the coolant temperature or pressure of the engine coolant passage and the internal coolant temperature or pressure of the exhaust heat recovery system.