Method for operating an air-conditioning system of a vehicle
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Solution Overview
Problem
Existing air conditioning systems for vehicles face inefficiencies during defrosting operations, where icing of heat exchangers occurs, leading to energy-intensive counter-heating to maintain interior comfort, especially when transitioning from heat pump to cooling mode, resulting in excessive cooling and energy loss.
Innovation Solution
The system operates heat exchangers in parallel as both cooling devices and evaporators during defrosting, allowing for efficient heat transfer and reduced counter-heating needs by reversing refrigerant flow sequences and adjusting mass flows through separate refrigerant circuits, thereby preventing excessive interior cooling and effectively addressing icing without disrupting desired interior temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the air conditioning system is operated in cooling mode to defrost the first heat exchanger, then the icing problem is resolved, but the interior experiences excessive cooling and comfort is reduced
Solution Approach 1:
The patent segments the heat exchanger into two functional parts: the first heat exchanger (evaporator) that gets iced during heat pump operation, and the second heat exchanger (condenser) that remains functional. During defrosting, only the first heat exchanger is switched to cooling mode while the second continues heating, allowing localized defrosting without compromising overall interior heating.
Solution Approach 2:
The patent applies local quality by enabling different operational modes in different parts of the system simultaneously. The first heat exchanger operates in cooling mode for defrosting while the second heat exchanger maintains heating function, creating a spatial and functional differentiation that resolves the contradiction between defrosting and interior heating.
2Reliability
If the air conditioning system switches from heat pump mode to cooling mode for defrosting, then the first heat exchanger is heated, but energy-intensive counter-heating is required to maintain interior temperature
Solution Approach 1:
The patent ensures continuity of useful action by maintaining the second heat exchanger in heating mode throughout the defrosting process. This continuous heating action compensates for the temporary cooling of the first heat exchanger, eliminating the need for additional energy-intensive counter-heating measures and maintaining overall system efficiency.
Solution Approach 2:
The patent merges the defrosting function and heating function into a single coordinated operation. By switching only the first heat exchanger to cooling mode while keeping the second in heating mode, the system combines defrosting and heating actions simultaneously, avoiding the energy waste of separate defrosting and counter-heating operations.
3Use of energy by moving object
If the first heat exchanger is operated as evaporator during heat pump mode, then heat absorption from ambient air is achieved, but icing occurs on the heat exchanger surface
Solution Approach 1:
The patent implements periodic action by alternating the operational mode of the first heat exchanger between heat pump (evaporator) mode and defrosting (cooling) mode. This periodic switching prevents permanent icing accumulation while maintaining overall heat pump functionality, as the system cycles between heat absorption and ice melting phases.
Solution Approach 2:
The patent converts the harmful effect of cooling the first heat exchanger (which causes icing) into a beneficial defrosting action. By intentionally switching the first heat exchanger to cooling mode during defrosting cycles, the system uses the same cooling mechanism that causes icing to melt the accumulated ice, transforming a harmful effect into a self-cleaning benefit.
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 approach reduces energy-intensive counter-heating requirements, maintains interior comfort, and ensures efficient operation by preventing excessive cooling during defrosting, effectively counteracting icing without impacting the desired interior temperature.
Implementation Method 1
heat is transferred from the medium mentioned to the refrigerant via the first heat exchanger
Implementation Method 2
heat is transferred from the refrigerant to the aforementioned medium via the first heat exchanger
Implementation Method 3
the respective heat exchanger is operated in parallel as a cooling device for cooling the refrigerant and as an evaporator for evaporating the refrigerant
Data Source
Figure 1~2
AI summary
The invention relates to a method for operating an air-conditioning system (10) which, in heat pump operation, can be used as a heat pump for heating an interior of a vehicle and, in cooling operation, can be used as a refrigeration unit for cooling the interior, which system has a compressor (16) which compresses a refrigerant in heat pump operation and in cooling operation, at least one first heat exchanger (20) which in heat pump operation is used as an evaporator for evaporating the refrigerant, and in cooling operation is used as a cooling device for cooling the refrigerant, and has at least one second heat exchanger (24) which in heat pump operation is operated as a cooling device for cooling the refrigerant, and in cooling operation is operated as an evaporator for evaporating the refrigerant, wherein the air-conditioning system (10) is operated in de-icing operation in which the respective heat exchanger (20, 24) is operated in parallel as a cooling device for cooling the refrigerant and as an evaporator for evaporating the refrigerant.