Vehicle Cabin Heating Source Switching During Heat Pump Defrost
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Solution Overview
Problem
Conventional vehicle air-conditioning systems face challenges in achieving required heating capacity when hot water from waste heat is not available, particularly due to low temperatures and frost deposition on outdoor heat exchangers, which can hinder heat pump operation.
Innovation Solution
A vehicle air-conditioning apparatus incorporating a hot water heater core, a heat pump, an electric heater, and a controller that selects the most efficient heat source among these components to maintain heating capacity, ensuring continuous operation even when hot water is not usable.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If heating is performed using only a heat pump when hot water temperature is low, then the system can operate without hot water, but the required heating capacity cannot be obtained
Solution Approach 1:
The patent combines multiple heating sources (hot water heater core, heat pump, and electric heater) into a unified heating system. The controller integrates these different heating mechanisms to work together, allowing the system to achieve required heating capacity by combining the output of multiple sources when hot water temperature is insufficient.
Solution Approach 2:
The heating system is designed with multi-functionality by incorporating three different heating mechanisms that can operate independently or in combination. This universal heating approach ensures that regardless of hot water temperature conditions, the system can always achieve the required heating capacity by selecting or combining appropriate heating sources.
2Reliability
If inverse cycle-type defrosting operation is performed to remove frost from outdoor heat exchanger, then frost is removed, but heating by the heat pump cannot be performed during the defrosting operation
Solution Approach 1:
The system prepares for potential heating interruptions during defrosting by having alternative heating sources (hot water heater core and electric heater) ready to take over. This cushioning approach ensures that when the heat pump must be stopped for defrosting, the heating function continues without interruption through other available heating mechanisms.
Solution Approach 2:
During defrosting operation, the system temporarily discards heat pump heating function to remove frost from the outdoor heat exchanger, then recovers heating capability by switching to alternative heating sources (hot water heater core or electric heater), ensuring continuous heating operation throughout the defrosting process.
3Loss of energy
If hot water is used for heating when temperature is sufficient, then energy saving is achieved, but heating cannot be performed when hot water temperature is low
Solution Approach 1:
The heating system dynamically adjusts its operation mode based on hot water temperature conditions. When hot water temperature is sufficient, the system uses the hot water heater core for energy-efficient heating. When hot water temperature becomes low, the controller dynamically switches to or combines with heat pump and/or electric heater to maintain required heating capacity, ensuring both energy efficiency and heating reliability under varying conditions.
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 ensures a required heating capacity is maintained by utilizing a combination of hot water, heat pump, and electric heater, allowing for energy-efficient heating even in cases where hot water is not sufficient, and preventing heating disruptions during defrosting operations.
Implementation Method 1
a hot water heater core provided in a hot water circuit in which cooling water circulates in a heat source to recover waste heat of the heat source, and configured to exchange heat between the cooling water heated by the waste heat of the heat source and air to heat the air
Implementation Method 2
a heat pump configured to exchange heat between a refrigerant discharged from a refrigerant compressor and air by using an indoor heat exchanger to heat the air
Implementation Method 3
an electric heater configured to heat air to heat the inside of the vehicle
Data Source
AI summary
A vehicle air-conditioning apparatus includes: a hot water heater core provided in a hot water circuit in which cooling water circulates in a heat source to recover waste heat of the heat source, and configured to exchange heat between the cooling water heated by the waste heat of the heat source and air to heat the air, thereby heating an inside of a vehicle by using the heated air; a heat pump configured to exchange heat between a refrigerant discharged from a refrigerant compressor and air by using an indoor heat exchanger to heat the air, thereby heating the inside of the vehicle by using the heated air; an electric heater configured to heat air to heat the inside of the vehicle; and a controller configured to select at least one of the hot water heater core, the heat pump and the electric heater to perform a heating operation.