Electrically Heated Catalyst Valve Control for Cold-Start Freeze Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing exhaust purification systems with electrically heated catalysts face challenges in reducing power consumption and preventing the exhaust pipe from blocking due to plug freezing under ultra-low temperatures, which affects the catalyst's ability to activate quickly during cold starts.
Innovation Solution
An exhaust purification device with a vacuum layer covering the electrically heated catalyst, combined with upstream and downstream opening/closing valves, is controlled to discharge residual combustion gas, heat the catalyst to a target temperature, and maintain thermal insulation, reducing power consumption and preventing freezing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the electrically heated catalyst is heated to activation temperature quickly, then the catalyst activates rapidly during cold start, but the power consumption increases significantly
Solution Approach 1:
The system performs preliminary heating of the electrically heated catalyst before the engine starts, using the electric motor to motor the engine and heat the catalyst in advance. This preliminary action ensures the catalyst reaches activation temperature before cold start, eliminating the need for high-power heating during the critical cold start period and thus reducing overall power consumption.
Solution Approach 2:
The system maintains continuous, low-power heating of the catalyst after the initial heating phase, keeping the catalyst at or near activation temperature during engine operation. This continuous action prevents temperature drops that would require high-power reheating, thereby maintaining rapid activation capability while reducing peak power consumption requirements.
2Temperature
If the exhaust pipe is sealed to provide thermal insulation, then the catalyst retains heat better, but the exhaust pipe may block due to plug freezing under ultra-low temperatures
Solution Approach 1:
The system changes the temperature parameter by actively heating the exhaust pipe and catalyst assembly using the electric motor and heater elements. This temperature maintenance prevents water vapor condensation and freezing in the exhaust pipe, eliminating the blocking risk while preserving the thermal insulation benefits of the sealed configuration under ultra-low temperature conditions.
Solution Approach 2:
The system converts the potentially harmful effect of cold temperatures into a beneficial heating mode, using the electric motor and heater elements to actively warm the exhaust system. This transforms the freezing risk into a controlled heating process that prevents blockages while maintaining thermal insulation, turning a harmful environmental condition into a manageable operational parameter.
3Use of energy by moving object
If the electric motor is used to motor the engine for heating, then the catalyst can be heated without engine power, but the engine requires additional operational steps
Solution Approach 1:
The electric motor serves multiple functions: it acts as a generator to produce electricity for heating the catalyst, and it also motors the engine during cold start. This multi-functionality eliminates the need for separate heating power sources and integrates the heating function into existing engine operation, reducing overall system complexity despite the additional control procedures.
Solution Approach 2:
The system uses the engine's own rotational energy, captured by the electric motor during deceleration or idle periods, to power the heating of the catalyst. This self-service approach recycles energy that would otherwise be wasted, using the engine's own operation to facilitate its own cold start process without requiring external power sources or complex additional systems.
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 reduces power consumption and prevents the exhaust pipe from blocking by maintaining the electrically heated catalyst at an optimal temperature, ensuring rapid activation during cold starts without the need for excessive heating.
Implementation Method 1
The exhaust pipe has a vacuum layer that covers at least an entire side surface of the electrically heated catalyst
Implementation Method 2
The electrically heated catalyst is configured to be heated by power supply, and to purify exhaust of the engine at a predetermined activation temperature or higher
Implementation Method 3
drive the electric motor to motor the engine, discharge residual combustion gas from inside the engine and the exhaust pipe, and replace the residual combustion gas with fresh air
Data Source
AI summary
An exhaust purification device for a vehicle with an engine and an electric motor includes: an electrically heated catalyst that is heated by power supply to purify engine exhaust at a predetermined activation temperature or higher; an exhaust pipe with a vacuum layer covering at least an entire side surface of the catalyst; first and second opening/closing valves; and a control unit that controls the power supply and driving of the valves. Upon closing the valves after the vehicle is stopped and the engine is shut down, , the control unit drives the motor to motor the engine and discharge combustion gas from the engine and exhaust pipe, and replaces it with fresh air. The control unit then closes the second valve to heat the catalyst to a target temperature, and thereafter, when the temperature reaches the target temperature, stops the power supply and closes the first valve.