Multi-Unit Air Conditioner Control for Stable Evaporation Temperature
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Solution Overview
Problem
In multi-type air conditioners, stable air conditioning operations are compromised due to fluctuations in liquid pipe temperature and air volume caused by other indoor units switching their thermostats and air volume settings, leading to instability in temperature control.
Innovation Solution
The air conditioner features indoor-side controllers that adjust capacity based on degree of superheating, degree of supercooling, air volume, evaporation temperature, or condensation temperature, with the outdoor unit setting temperatures that prioritize stability and energy efficiency, allowing indoor units to maintain stable operations regardless of other units' conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If indoor units perform capacity control on the basis of the liquid pipe temperature that they itself have detected, then the control responds quickly to temperature changes, but the liquid pipe temperature fluctuates frequently when other indoor units switch thermostats, causing unstable air conditioning operations
Solution Approach 1:
The patent introduces an intermediary mechanism where the outdoor unit acts as a mediator to manage evaporation temperature settings. Instead of each indoor unit independently controlling based on its own liquid pipe temperature (which causes fluctuations), the outdoor unit receives requests from multiple indoor units and determines a unified evaporation temperature that balances all demands. This intermediary control eliminates the instability caused by individual units reacting independently to temperature changes.
2Stability of the object's composition
If the outdoor unit sets an evaporation temperature different from what indoor units request, then system-wide stability is improved, but the indoor units must adjust their expected temperatures, potentially increasing control complexity
Solution Approach 1:
The patent applies parameter changes by allowing the outdoor unit to adjust the evaporation temperature parameter based on the collective needs of multiple indoor units. When the outdoor unit determines that a different evaporation temperature is necessary for system stability, it modifies this key parameter and notifies the indoor units. The indoor units then adjust their capacity control calculations based on the new evaporation temperature, maintaining stability without excessive complexity.
Solution Approach 2:
The system implements a feedback mechanism where indoor units send their temperature requests to the outdoor unit, the outdoor unit determines an appropriate evaporation temperature, and then notifies the indoor units of the decision. The indoor units use this feedback to adjust their capacity control. This closed-loop feedback system coordinates temperature settings across all units while maintaining overall system stability.
3Use of energy by moving object
If indoor units optimize degree of superheating and air volume independently, then energy efficiency improves, but coordination with other indoor units becomes difficult, potentially causing instability
Solution Approach 1:
The patent merges the independent optimization functions of multiple indoor units into a coordinated system through the outdoor unit. Each indoor unit still optimizes its degree of superheating and air volume for energy efficiency, but these optimizations are performed within the framework of a unified evaporation temperature setting determined by the outdoor unit. This combination allows individual energy optimization while preventing the instability that would result from uncoordinated independent adjustments.
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 ensures stable air conditioning operations by optimizing the refrigerant-side heat transfer coefficient, minimizing air volume, and preventing room temperature deviations from set values, thereby enhancing energy efficiency and system stability.
Implementation Method 1
an evaporation temperature or a condensation temperature
Implementation Method 2
capacity calculation using a heat exchange function whose parameters comprise differences between room temperatures and the evaporation temperature
Implementation Method 3
an evaporation temperature or a condensation temperature that is different from the value of an evaporation temperature or a condensation temperature that any of the indoor unit has requested
Implementation Method 4
control that adjusts capacity on the basis of a degree of superheating or a degree of supercooling
Implementation Method 5
control that adjusts capacity on the basis of a degree of superheating or a degree of supercooling
Data Source
AI summary
An air conditioner includes an outdoor unit and a plurality of indoor units connected to the outdoor unit. The outdoor unit sometimes sets an evaporation temperature or a condensation temperature that is different from a value that any of the indoor units has requested from the outdoor unit. The indoor units have indoor-side controllers that perform capacity control that adjusts capacity based on a degree of superheating or a degree of supercooling, an air volume, or an evaporation temperature or a condensation temperature while calculating a requested capacity that is determined from a current room temperature and a set room temperature. The indoor-side controllers, when performing the capacity control, determine at least one of the air volume and a target value of the degree of superheating or the degree of supercooling based on the evaporation temperature or the condensation temperature that is set by the outdoor unit.