Coolant Control System for Diesel Exhaust Fluid Injector Vaporization
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Solution Overview
Problem
Internal combustion engines face overheating issues due to excessive heat generation, leading to potential damage and reduced component lifespan, which existing coolant systems struggle to mitigate effectively, especially when the diesel exhaust fluid injector vaporizes coolant, causing vapor-locking and ineffective cooling.
Innovation Solution
A coolant control system that includes a second radiator, a diesel exhaust fluid injector, a fuel heat exchanger, and an engine control module (ECM) to monitor and control the coolant pump's duty cycle based on DEF injector temperature, oscillating the duty cycle to mitigate vaporization and identify low-coolant conditions, thereby preventing damage and ensuring effective cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the coolant system uses a conventional single-radiator design, then the system structure is simple, but the coolant cannot be effectively cooled when the DEF injector vaporizes it, leading to ineffective cooling and potential engine damage
Solution Approach 1:
The patent divides the single radiator into two separate radiators: a first radiator for general engine cooling and a second radiator specifically for cooling the DEF injector. This segmentation allows each radiator to be optimized for its specific function, ensuring reliable cooling even when vaporization occurs in the DEF injector circuit.
Solution Approach 2:
The patent introduces a heat exchanger as an intermediary component between the DEF injector and the coolant system. This heat exchanger transfers heat from the DEF injector to the coolant, preventing direct contact between hot exhaust gases and coolant while maintaining effective cooling.
2Reliability
If the coolant pump operates at high duty cycle to prevent vaporization, then cooling effectiveness improves, but energy consumption increases and the system may identify false low-coolant conditions
Solution Approach 1:
The patent implements a feedback control system where the ECM continuously monitors DEF injector temperature and coolant conditions. Based on this feedback, the system dynamically adjusts the coolant pump duty cycle, increasing it only when vaporization is detected and reducing it when cooling is sufficient, thereby optimizing energy consumption while preventing vaporization.
Solution Approach 2:
The patent makes the coolant pump duty cycle dynamic rather than static. The system can oscillate the duty cycle between different levels based on real-time temperature monitoring, allowing the pump to adapt its operation to current thermal conditions and avoid unnecessary energy consumption during normal operating conditions.
3Reliability
If the system oscillates the coolant pump duty cycle to mitigate vaporization, then vaporized coolant conditions are reduced, but the control system complexity increases
Solution Approach 1:
The patent employs periodic oscillation of the coolant pump duty cycle as a control strategy. The ECM alternates the duty cycle between high and low states in a controlled manner, creating periodic action that prevents vaporization by ensuring adequate cooling pulses while allowing energy-saving intervals.
Solution Approach 2:
The system uses self-service control where the ECM automatically monitors temperature conditions and adjusts pump operation without external intervention. The oscillation logic is embedded in the control module, allowing the system to self-regulate and mitigate vaporization conditions through programmed responses to temperature thresholds.
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 system effectively identifies and mitigates vaporized coolant conditions, preventing damage to vehicle hardware by oscillating the coolant pump's duty cycle and engaging alarms for low-coolant conditions, ensuring consistent and efficient cooling of the engine and exhaust system components.
Implementation Method 1
a fuel heat exchanger that receives fuel flowing from a fuel rail to a fuel tank of the vehicle, that receives coolant output from the DEF injector, and that transfers heat between coolant flowing through the fuel heat exchanger and fuel flowing through the fuel heat exchanger
Implementation Method 2
The radiator transfers heat from the engine coolant to air passing the radiator
Implementation Method 3
a coolant pump that pumps coolant to a second radiator that is different than a first radiator that receives coolant from an engine of the vehicle
Data Source
AI summary
A coolant control system of a vehicle includes a coolant pump that pumps coolant to a second radiator that is different than a first radiator that receives coolant from an engine of the vehicle. A diesel exhaust fluid (DEF) injector injects a DEF into an exhaust system and receives coolant output from the second radiator. A fuel heat exchanger transfers heat between coolant and fuel flowing therethrough. An engine control module is configured to determine a temperature of the DEF injector, control a duty cycle of the coolant pump, determine a vaporized condition of the coolant based on a DEF injector temperature, optionally further, in response to determining a vaporized condition of the coolant, implement a vapor purge by oscillating the duty cycle of the coolant pump, and optionally further identify a low-coolant condition of the coolant control system based on the vapor purges implemented during a time period.