Vehicular Heater Flow Rate Control for Exhaust Heat Recovery
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Solution Overview
Problem
Conventional vehicular heaters experience a decrease in heating performance due to increased water flow resistance when the vehicle engine is operating, as the cooling water passes through both the engine and an alternative heat source, leading to inefficient heat recovery and potential thermal shock loads on the heater core.
Innovation Solution
A vehicular heater system with a heat medium circuit that includes a first flow path connected to the power unit and a second flow path connected to a different heat source, featuring a flow rate control unit that adjusts the flow rates to prioritize the power unit flow rate over the heat source device flow rate when the power unit is operating, reducing water flow resistance and maintaining heat medium temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If cooling water passes through both the engine and alternative heat source in series, then heat recovery from the engine is achieved, but water flow resistance increases and heating performance decreases
Solution Approach 1:
The heat medium circuit is segmented into multiple parallel flow paths: a first flow path through the power unit and a second flow path through the heat source device. This segmentation allows the heat medium to flow through both heat sources simultaneously rather than in series, reducing flow resistance while recovering heat from both sources.
Solution Approach 2:
The patent merges the heat recovery functions of the power unit and alternative heat source by connecting them in parallel within the heat medium circuit. The flow rate control unit coordinates both paths to work together, combining their heat output to maintain heating performance while reducing overall flow resistance.
2Loss of energy
If cooling water flows through the engine and heater core, then exhaust heat is recovered, but thermal shock loads occur on the heater core
Solution Approach 1:
The flow rate control unit performs preliminary action by adjusting the flow rate of cooling water before it enters the heater core. It ensures that the heat medium temperature is maintained within appropriate ranges and prevents excessive temperature changes that could cause thermal shock to the heater core.
Solution Approach 2:
The system implements feedback control through the flow rate control unit, which monitors the heat medium temperature and adjusts the flow rates in both the first and second flow paths accordingly. This feedback mechanism prevents thermal shock by maintaining stable temperatures in the heater core while still recovering exhaust heat effectively.
3Loss of energy
If flow rate through power unit is increased to improve heat recovery, then exhaust heat utilization improves, but water flow resistance increases
Solution Approach 1:
The flow rate control unit dynamically adjusts the flow rates in both the first flow path (power unit) and second flow path (heat source device) based on operating conditions. This dynamic control allows the system to optimize heat recovery from the power unit while compensating for flow resistance by adjusting the alternative heat source contribution.
Solution Approach 2:
The system changes the flow rate parameter distribution between two parallel paths. By increasing flow rate in the second path when the first path experiences high resistance, the overall system maintains effective heat recovery while reducing the harmful effect of water flow resistance through parameter optimization.
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 recovers exhaust heat from the power unit, maintains heating performance, and reduces thermal shock loads on the heater core by optimizing flow rates and utilizing exhaust heat efficiently, thereby enhancing heating efficiency and preventing excessive cooling of the heat medium.
Implementation Method 1
a heater core that heats the vent air blown by the blower via heat exchange with a heat medium
Implementation Method 2
a circulator that circulates the heat medium in the heat medium circuit
Implementation Method 3
a blower that blows vent air into a vehicle compartment which is a space to be heated
Data Source
AI summary
A vehicular heater includes a heat medium circuit connected to a heater core that heats vent air via heat exchange with a heat medium. The heat medium circuit includes a first flow path connected to the heater core through a power unit, and a second flow path arranged in parallel with the first flow path and connected to the heater core through a heat source different from the power unit. A controller adjusts a first flow rate of the heat medium in the first flow path to be larger than a second flow rate of the heat medium in the second flow path when the power unit is operating.