Multiple-type air conditioner
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Solution Overview
Problem
Conventional multiple-type air conditioners incorrectly control the expansion valve, leading to refrigerant stagnation on the stopped side, causing unnecessary warming due to increased refrigerant circulation, even when the refrigerant is insufficient on the operating side.
Innovation Solution
A multiple-type air conditioner with temperature detectors for the refrigerant in the heat exchanger, refrigerant outlet, and outside air, and a control unit that adjusts the expansion valve's opening degree based on a calculated ratio of temperature differences to prevent refrigerant stagnation and ensure sufficient refrigerant flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the expansion valve is controlled to open based on temperature difference alone, then refrigerant stagnation is prevented, but refrigerant circulation increases causing unnecessary warming
Solution Approach 1:
The patent changes the control parameter from simple temperature difference to a ratio of temperature differences. Specifically, it calculates the ratio of (heat exchanger intermediate temperature - heat exchanger outlet temperature) to (heat exchanger intermediate temperature - outside air temperature). This parameter transformation allows the system to distinguish between legitimate refrigerant circulation needs and situations where expansion valve opening causes unnecessary warming, thereby resolving the contradiction between preventing refrigerant stagnation and avoiding energy loss.
2Quantity of substance
If the expansion valve opening degree is increased to prevent refrigerant insufficiency, then refrigerant circulation amount increases, but capacity shortage occurs on the operating side
Solution Approach 1:
The patent implements a feedback control mechanism where the expansion valve opening degree is continuously adjusted based on the calculated ratio of temperature differences. The control unit monitors the thermal state of the heat exchanger and dynamically adjusts the expansion valve to maintain optimal refrigerant circulation. This feedback approach ensures that refrigerant circulation is increased only when necessary to prevent insufficiency, while avoiding over-circulation that would cause capacity shortage on the operating side.
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
Enables operation of multiple indoor or outdoor units without capacity shortage or refrigerant insufficiency, minimizing unnecessary heating and refrigerant circulation, and optimizing refrigerant management.
Implementation Method 1
a first heat exchanger; a second heat exchanger
Implementation Method 2
natural heat radiation
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A multiple-type air conditioner (100) is provided with a first indoor unit (110A) and a second indoor unit (110B). When the first indoor unit (110A) is stopped and the second indoor unit (110B) operates with a second indoor heat exchanger (111B) functioning as a condenser, the opening degree of a first indoor expansion valve (140A) is increased if the ratio of a difference between a temperature detected by a first heat exchanger intermediate temperature detector (112A) and a temperature detected by a first heat exchanger outlet temperature detector (113A) to a difference between the temperature detected by the first heat exchanger intermediate temperature detector (112A) and the air temperature is greater than a target value, and the opening degree of the first indoor expansion valve (140A) is reduced if the ratio is lower than the target value.