Heat Exchanger Switching for Partial-Load Refrigerant Control
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Solution Overview
Problem
Multi-split air-conditioning systems face low operating reliability due to excessive refrigerant, leading to low condensing pressure, insufficient liquid feeding power, and reduced refrigerating capacity, especially during partial load operations.
Innovation Solution
An air conditioning system with a control mechanism that allows heat exchangers to switch between a first working state for draining liquid and a second state for storing liquid, regulated by load parameters to optimize refrigerant circulation, using switching valves and electronic expansion valves to manage refrigerant flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a multi-split air-conditioning system operates with a single outdoor unit connected to multiple indoor units, then installation is facilitated and installation space is saved, but operating reliability decreases under low load conditions
Solution Approach 1:
The outdoor heat exchanger is divided into multiple independent heat exchange elements that can be independently controlled. Each element can be selectively activated or deactivated based on load requirements, allowing the system to maintain reliable operation under partial load conditions while preserving the multi-split configuration benefits.
Solution Approach 2:
The system dynamically adjusts the number of active heat exchange elements in the outdoor unit based on real-time load conditions. This dynamic reconfiguration allows the system to optimize performance and reliability for each operating condition while maintaining the flexible multi-split architecture.
2Productivity
If the outdoor heat exchanger volume is large relative to indoor heat exchangers, then the system can handle high load conditions, but liquid feeding power becomes insufficient under low load conditions
Solution Approach 1:
The outdoor heat exchanger is segmented into multiple independent elements that can be selectively activated. Under low load conditions, only a subset of these elements is activated, effectively reducing the active heat exchange volume to match the load requirements and maintain adequate liquid feeding power.
Solution Approach 2:
The system changes the effective volume parameter of the outdoor heat exchanger by selectively activating different numbers of heat exchange elements. This parameter adjustment ensures that the heat exchanger volume is optimized for each load condition, preventing liquid feeding power insufficiency during partial load operation.
3Quantity of substance
If there is much circulating refrigerant in the system, then the system has sufficient refrigerant for high load operation, but condensing pressure becomes too low under partial load conditions
Solution Approach 1:
The system extracts or removes a portion of the circulating refrigerant from the heat exchanger circuit under partial load conditions by deactivating certain heat exchange elements. This reduction in circulating refrigerant quantity prevents condensing pressure from dropping too low while maintaining sufficient refrigerant for the active components.
Solution Approach 2:
The system dynamically adjusts the refrigerant quantity parameter in the circulation loop by controlling the activation state of different heat exchange elements. This parameter optimization ensures that condensing pressure remains within the optimal range for throttle mechanism operation during partial load conditions.
4Quantity of substance
If refrigerant accumulates in the condenser or liquid accumulator during partial load operation, then the system maintains refrigerant supply, but the pressure difference across the valve becomes too small
Solution Approach 1:
The system dynamically adjusts the refrigerant accumulation in the liquid accumulator by selectively activating or deactivating heat exchange elements. This dynamic control maintains an optimal pressure difference across the expansion valve by preventing excessive refrigerant accumulation during partial load operation.
Solution Approach 2:
The system optimizes the pressure difference parameter across the expansion valve by dynamically adjusting refrigerant accumulation in the liquid accumulator. This is achieved by controlling the activation state of heat exchange elements to match the load requirements and maintain adequate pressure differential for proper throttle mechanism operation.
5Quantity of substance
If the pressure difference across the valve is too small, then refrigerant circulation is maintained, but liquid feeding power becomes insufficient
Solution Approach 1:
The system optimizes the pressure difference parameter across the expansion valve by dynamically adjusting the number of active heat exchange elements. This parameter optimization ensures that liquid feeding power remains sufficient for reliable operation while maintaining appropriate refrigerant circulation for the current load 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
This solution improves operating comfort and reliability by reducing circulating refrigerant during low load conditions, optimizing pressure differences, and enhancing the performance of throttle mechanisms, thereby ensuring reliable operation and energy efficiency.
Implementation Method 1
The heat exchanger drains liquid when in the first working state and stores liquid when in the second working state
Implementation Method 2
at least one heat exchanger... configured to control the corresponding heat exchanger to switch between a first working state and a second working state
Implementation Method 3
The heat exchanger drains liquid when in the first working state
Implementation Method 4
at least one heat exchanger... configured to control the corresponding heat exchanger to switch between a first working state and a second working state
Data Source
AI summary
An air conditioning system and a control method are provided. The air conditioning system includes: at least one heat exchanger (1, 2); and at least one control mechanism. Each control mechanism is connected to one of the at least one heat exchanger (1, 2) and is configured to control the corresponding heat exchanger to switch between a first working state and a second working state. The heat exchanger (1, 2) drains liquid when in the first working state and stores liquid when in the second working state.