HVAC Ducting Split Airstream for Single-Sensor Temperature Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing HVAC systems for vehicles rely on indirect temperature measurements, which are dependent on engine characteristics and require multiple sensors for accurate air discharge temperature control, especially in cold climates, leading to inefficiencies and increased costs.
Innovation Solution
An HVAC system with ducting that splits the airstream into portions passing through and bypassing a heater element, using a single temperature sensor downstream of the PTC element to directly measure the temperature of the airstream portion, allowing for independent control and prediction of air discharge temperature across multiple outlets with fewer sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If indirect temperature measurement methods are used (measuring engine coolant temperature to predict heater core temperature), then the temperature measurement becomes dependent on systems outside the HVAC system, but this reduces the number of temperature sensors needed within the HVAC system
Solution Approach 1:
The invention extracts the temperature measurement function from the engine cooling system and relocates it directly to the HVAC system by placing a temperature sensor on the heater core. This allows the HVAC system to independently measure its own operating parameters without relying on engine coolant temperature correlations, thereby resolving the contradiction between sensor reduction and system independence.
Solution Approach 2:
The temperature sensor acts as an intermediary element that directly measures the heater core temperature, serving as a bridge between the heating system and the control system. This eliminates the need for indirect measurement through engine coolant temperature while maintaining simple sensor placement.
2Measurement precision
If multiple temperature sensors are installed in each air outlet to achieve accurate temperature values, then measurement precision is improved, but device complexity and cost increase due to the high number of sensors required
Solution Approach 1:
Instead of placing physical temperature sensors in each air outlet, the system creates a virtual model of the HVAC system that predicts outlet temperatures based on the single heater core temperature measurement combined with airflow data. This copying approach achieves accurate temperature information without the complexity of multiple physical sensors.
Solution Approach 2:
The single temperature sensor on the heater core serves multiple functions: it measures the temperature of the heated air stream, provides input for predicting temperatures at multiple different outlets, and enables control of the entire HVAC system. This universal measurement point replaces what would otherwise require multiple specialized sensors.
3Device complexity
If the HVAC system uses engine coolant temperature correlation to predict air discharge temperature, then the system can operate with fewer sensors, but adaptability to different engine characteristics is reduced
Solution Approach 1:
The invention extracts the temperature measurement from the engine system and places it directly in the HVAC system. This extraction eliminates the dependency on engine-specific characteristics and coolant temperature correlations, allowing the HVAC system to work independently with any engine type without requiring re-calibration or new correlation models.
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 solution provides accurate and independent temperature control within the HVAC system, reducing the need for multiple sensors and enabling cost-effective prediction of air discharge temperature across all outlets, regardless of engine changes or heat source variations.
Implementation Method 1
a heater element comprising a heat exchanger and a PTC element
Implementation Method 2
a heater element comprising a heat exchanger and a PTC element
Data Source
AI summary
The present invention relates to an HVAC system (1) for a vehicle. The HVAC system comprises ducting, a heater element (15; 45, 47) and at least one air outlet (53 1 , 53 2 , ...53 n ). The ducting is arranged so that an airstream passing through the HVAC system is split into a first airstream portion (19) passing through the heater element (15; 45, 47) and a second airstream portion (21) by-passing the heater element (15; 45, 47). The ducting is further arranged so that an outlet airstream going through the at least one air outlet (53 1 , 53 2 , ...53 n ) is a combination of air from the first (19) and second (21) airstream portions. Further, a first temperature sensor (49) is located downstream of the heater element (15; 45, 47) for determining the temperature in the first airstream portion (19). The invention further relates to a method for controlling mean air discharge temperature, a method for predicting outlet air discharge temperature and a use of temperature data measured in the first airstream portion (19) downstream of a heater element (15; 45, 47).