Coolant-Loop Heat Pump Control for EV Cabin Heating Load Reduction
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Solution Overview
Problem
Electric vehicles face challenges in efficiently managing thermal energy for cabin heating during cold weather, leading to increased energy consumption and reduced range.
Innovation Solution
A coolant-loop based heat pump system with a controller that adjusts coolant pathways and compressor loads to minimize energy usage, utilizing a low-temperature radiator, rechargeable energy storage system, and refrigerant loop to optimize heating efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a coolant heater is used for cabin heating, then heating function is provided, but energy consumption increases and vehicle range decreases
Solution Approach 1:
The patent merges the coolant heater with the heat pump system, allowing the compressor to serve dual purposes: refrigeration cycling and heat generation. The coolant heater is integrated into the coolant loop and receives heated coolant from the heat pump, combining heating functions with the existing refrigeration system to reduce overall energy consumption.
Solution Approach 2:
The heat pump system is designed to perform multiple functions: refrigeration, heating, and cabin climate control. The compressor and coolant loop serve both cooling and heating purposes depending on operational mode, eliminating the need for separate heating systems and reducing total energy requirements.
2Power
If coolant heater load is increased to provide sufficient heating, then heating capacity is improved, but energy consumption increases
Solution Approach 1:
The controller continuously monitors coolant temperature, cabin temperature, and heat pump operational parameters. Based on this feedback, the controller dynamically adjusts compressor load, coolant flow distribution, and heat exchanger operation to provide sufficient heating capacity while minimizing energy consumption through optimal control strategies.
Solution Approach 2:
The system dynamically adjusts operational parameters including compressor speed, coolant flow rates, and heat exchanger activation based on real-time heating demands and environmental conditions. This dynamic operation allows the system to match heating capacity to actual needs, avoiding excessive energy consumption while maintaining required heating performance.
3Use of energy by moving object
If compressor load is maximized for heat recovery, then energy efficiency is improved, but suction pressure may drop below operational threshold
Solution Approach 1:
The controller monitors suction pressure continuously and uses this feedback to adjust compressor operation. When suction pressure approaches the operational threshold, the controller modulates compressor load to maintain pressure above the threshold while still maximizing heat recovery efficiency within safe operational limits.
Solution Approach 2:
The system changes operational parameters including compressor speed, coolant flow rates, and heat exchanger configuration to optimize the balance between heat recovery efficiency and suction pressure maintenance. By adjusting these parameters dynamically, the system maintains efficient operation without compromising suction pressure below operational 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 reduces energy consumption for cabin heating, enhancing the vehicle's range by minimizing coolant heater load and maximizing compressor efficiency under varying ambient conditions.
Implementation Method 1
A coolant-to-refrigerant (C2R) heat exchanger is fluidly connected to the coolant loop and the refrigerant loop. The C2R heat exchanger is configured to transfer heat between the coolant circulating in the coolant loop and the refrigerant circulating in the refrigerant loop.
Implementation Method 2
A low-temperature radiator is located in the coolant loop downstream of the C2R heat exchanger. The low-temperature radiator is adapted to extract heat from ambient air to warm the coolant when a coolant temperature is lower than an ambient temperature.
Implementation Method 3
A compressor is located in the refrigerant loop. The controller is adapted to maximize the respective load of the compressor and maintain a threshold suction pressure for compressor operation.
Data Source
AI summary
A thermal management system for an electric vehicle includes a coolant loop having a pump configured to circulate a coolant in the coolant loop and one or more valves. A controller is adapted to control respective positions of the one or more valves for modifying the coolant pathway in the coolant loop. The system includes a coolant-to-refrigerant (C2R) heat exchanger fluidly connected to the coolant loop and a refrigerant loop. A low-temperature radiator is located in the coolant loop downstream of the C2R heat exchanger. A coolant heater is positioned in the coolant loop downstream of the low-temperature radiator and a compressor is located in the refrigerant loop. The controller is adapted to minimize energy usage for cabin heating in the electric vehicle by minimizing a respective load of the coolant heater, maximizing the respective load of the compressor, and maintaining a threshold suction pressure for compressor operation.