De-icing control in a vapor compression heat pump system
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Solution Overview
Problem
Vapor compression heat pump systems in electrified vehicles face inefficiencies and potential damage due to ice accumulation on heat exchangers, which existing technologies fail to address effectively while maintaining noise, vibration, and harshness standards during mode transitions.
Innovation Solution
A controller-mediated method that adjusts the compressor speed to generate sufficient heat to melt ice on the heat exchanger, utilizing a bumpless transfer algorithm to ensure smooth transitions and comply with predefined noise, vibration, and harshness standards, and activates climate control systems to maintain cabin conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the compressor speed is increased to generate heat to melt ice on the heat exchanger, then the de-icing effectiveness is improved, but the noise, vibration, and harshness increase
Solution Approach 1:
The system dynamically adjusts compressor speed based on real-time detection of ice conditions. The controller monitors heat exchanger temperature and ambient conditions, then modulates compressor speed accordingly - increasing it only when ice detection thresholds are met, and reducing it when ice conditions resolve, thereby balancing de-icing effectiveness with NVH comfort
Solution Approach 2:
The system changes the operating parameters of the compressor (speed, discharge temperature) in response to detected ice conditions. By adjusting these parameters dynamically rather than maintaining constant high speed, the system achieves effective de-icing while minimizing unnecessary noise and vibration during normal operation
2Productivity
If the compressor speed is adjusted rapidly to remove ice, then the de-icing speed is improved, but the system experiences harsh transitions and potential damage
Solution Approach 1:
The controller executes a bumpless transfer algorithm that prepares for speed transitions in advance. Before rapidly increasing compressor speed for de-icing, the system gradually adjusts intermediate parameters and activates climate control systems preemptively, ensuring smooth transitions that prevent mechanical shock and harshness while maintaining rapid de-icing capability
3Temperature
If the compressor operates at high speed continuously to prevent ice accumulation, then the heat generation is improved, but the energy consumption increases
Solution Approach 1:
Instead of continuous high-speed operation, the system employs periodic de-icing cycles triggered by ice detection algorithms. The controller monitors heat exchanger temperature, ambient conditions, and operating mode, then activates high-speed compressor operation only when ice conditions are detected, allowing normal efficient operation during ice-free periods
Solution Approach 2:
The system uses sensor feedback from heat exchanger temperature and ambient condition monitoring to dynamically control compressor speed. This closed-loop control ensures the compressor operates at high speed only when necessary for de-icing, rather than continuously, thereby reducing energy consumption while maintaining adequate heat generation when needed
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
Effectively removes ice accumulation on heat exchangers, enhancing system efficiency and preventing damage while minimizing compressor speed changes during mode transitions, thus maintaining performance and passenger comfort.
Implementation Method 1
adjust output of a compressor from a first speed to a second speed sufficient to generate an amount of heat in a refrigerant flowing through the heat exchanger to reduce the ice condition
Implementation Method 2
generate an amount of heat in a refrigerant flowing through the heat exchanger to reduce the ice condition
Implementation Method 3
refrigerant flowing through the heat exchanger to reduce the ice condition
Data Source
AI summary
A vapor compression heat pump (VCHP) system for an electrified vehicle and a method for de-icing the VCHP system is provided. The electrified vehicle may include a vehicle cabin, the VCHP system, and a controller. The VCHP system may be in thermal communication with the cabin and include an outside heat exchanger and a compressor. The controller may be configured to, in response to detection of a predefined ice condition associated with the outside heat exchanger, output commands to adjust a speed of the compressor to influence a temperature of refrigerant flowing through the compressor such that the refrigerant carries an amount of heat sufficient to eliminate the predefined ice condition within a preselected time period. The predefined ice condition may be a condition in which the heat exchanger has accumulated ice or is likely to accumulate ice.