Multi-Split Air Conditioner Outdoor Unit Frosting Balance Control
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Solution Overview
Problem
In multi-connection air conditioning systems, uneven frosting of outdoor units leads to inefficient heating capacity utilization, resulting in waste of resources, as all units must defrost when one is frosty, even if others are not, due to unbalanced output capacities and refrigerant distribution.
Innovation Solution
A method to control balanced frosting by calculating frosting degrees of all outdoor units, judging if an imbalance condition is met, and adjusting actual output capacities to ensure the total output capacity meets the required amount, by selectively turning units on or off based on frosting levels, thereby reducing differences in frosting degrees and optimizing heating capacity utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If all outdoor units are directly connected through pipelines, then the system structure is simple and easy to install, but when one outdoor unit needs defrosting, all outdoor units must enter defrosting state, resulting in low heating capacity utilization efficiency
Solution Approach 1:
The patent divides the outdoor unit set into multiple independent control groups based on pipeline connections and frosting characteristics. Each group can be controlled independently for defrosting operations, allowing units with different frosting degrees to be managed separately, thus improving heating capacity utilization efficiency while maintaining the simple direct connection structure.
2Adaptability or versatility
If outdoor units with different actual output capacities operate simultaneously, then the system can meet diverse heating demands, but the frosting degrees of individual outdoor units differ greatly, leading to uneven frosting distribution
Solution Approach 1:
The patent implements localized frosting control by monitoring and managing each outdoor unit's frosting degree individually based on its actual output capacity and operating conditions. Different control strategies are applied to different units according to their specific frosting states, allowing the system to maintain both operational flexibility and frosting uniformity.
Solution Approach 2:
The system continuously monitors the frosting degree of each outdoor unit and uses this feedback information to adjust operating parameters such as refrigerant flow distribution and defrosting timing. This closed-loop control ensures that units with different output capacities operate efficiently while maintaining relatively uniform frosting levels across the system.
3Reliability
If outdoor units enter defrosting state to remove frost, then heating effect is restored, but the defrosting process consumes time and reduces heating capacity availability
Solution Approach 1:
The system performs preliminary assessment of frosting degrees and predicts when defrosting will be necessary. By monitoring trends in frosting accumulation, the system can plan defrosting operations in advance, scheduling them during periods of lower heating demand or transitioning between operating modes, thus minimizing the impact on heating capacity availability.
Solution Approach 2:
The patent implements periodic defrosting cycles based on accumulated frosting degrees rather than continuous defrosting. Defrosting operations are scheduled at optimal intervals when frosting reaches predetermined thresholds, balancing the need to maintain heating effectiveness with the need to minimize defrosting frequency and associated time losses.
Data Source
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AI summary
The present invention relates to the technical field of air-conditioners, in particular to a method for controlling the balanced frosting of outdoor units in a multi-split air-conditioning system. The present invention aims to solve the problem in existing multi-split air-conditioning systems of resource waste caused by a low utilization efficiency of the heating capability of outdoor units as a result of some of the outdoor units entering a defrosting state when the heating capability is not fully utilized. According to the control method provided in the present invention, by means of determining whether an outdoor unit set satisfies a frosting unbalance condition, the actual output capability of outdoor units of the outdoor unit set is selectively controlled on the basis of the frosting degrees of all the outdoor units. Thus, the difference between the frosting degrees of different outdoor units in the outdoor unit set at the same time can be reduced, such that the heating capability of all the outdoor units can be fully utilized when the outdoor unit set enters a defrosting state.