Double-Effect Absorption HVAC for EV Battery Thermal Management
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Solution Overview
Problem
Conventional EV thermal management systems, such as heat-pumps and PTC heaters, significantly drain battery power for heating and cooling, reducing the vehicle's driving range and requiring extended time to warm up the passenger cabin in cold weather.
Innovation Solution
An HVAC-assisted thermal management system using an enhanced double-effect absorption process with a low voltage auxiliary battery, which indirectly heats and cools both the passenger cabin and the high voltage drivetrain battery, minimizing power loss from the higher voltage batteries through induction energy and a mixture of refrigerants like aqua ammonia, and nanoparticles for efficient heat transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional heat-pump and PTC heater systems are used for thermal management, then heating and cooling functions are provided, but battery power is significantly drained reducing driving range
Solution Approach 1:
The patent replaces the conventional mechanical compression-based refrigeration system with an absorption refrigeration system that uses thermal energy from the battery cooling loop to drive the cooling process. The absorption chiller uses heat from the battery thermal management system to evaporate refrigerant and drive the cooling cycle, substituting mechanical compression with thermally-driven absorption and desorption processes.
Solution Approach 2:
The patent creates a dual-purpose thermal management system where the battery cooling loop serves two functions: it cools the battery while simultaneously providing thermal energy to the absorption chiller for cabin cooling. The heat exchanger integrates these two functions by transferring heat from the battery coolant to the absorption chiller's refrigerant, allowing one system to serve multiple thermal management needs.
2Ease of operation
If high voltage battery power is used for cabin heating and cooling, then thermal comfort is maintained, but driving range is reduced due to power loss
Solution Approach 1:
The patent converts the waste heat generated by battery operation and the thermal energy in the battery cooling loop into useful cooling capacity for the cabin. The absorption chiller captures thermal energy that would otherwise be wasted and transforms it into refrigeration effect, turning a byproduct into a valuable resource for maintaining cabin comfort.
Solution Approach 2:
The absorption refrigeration system utilizes phase transitions of the refrigerant (evaporation, condensation, absorption, desorption) to create cooling effect. The refrigerant evaporates at low temperature to absorb heat, then condenses at high temperature releasing heat to the battery cooling loop, and cycles through absorption and desorption phases driven by thermal energy exchange.
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 extends the driving range of EVs by reducing battery power loss during thermal management, warming the cabin faster in winter conditions, and maintaining optimal thermal levels for both the battery and passenger compartment with lower energy consumption.
Implementation Method 1
an induction device by a low-voltage source which generates a magnetic field in order to provide high-thermal energy
Implementation Method 2
heat generator heated by the induction device with an aqua ammonia mixture or solution therein
Implementation Method 3
the solution evaporating and causing rising of the ammonia and water vapour
Implementation Method 4
an absorber with ionic water or DMAC solution wherein the ammonia is absorbed to configure a strong solution of an aqua ammonia
Implementation Method 5
a double heat exchanger communicating to and from the battery pack via inlet and outlet lines
Implementation Method 6
nanoparticles for efficient heat transfer
Data Source
AI summary
A system for minimizing higher voltage battery drain loss resulting from extreme environmental temperatures outside of an optimal operating range of an EV Battery. The HVAC assembly includes inputs for heating and cooling of the higher voltage battery using induction heat applied to an enhanced double-effect absorption process powered from a lower voltage auxiliary battery to limit draining of electrical power from the higher voltage battery.