Air conditioner
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Solution Overview
Problem
Existing air-conditioning apparatuses lack efficient detection methods for abnormal flow rates of heat media, which can lead to pump overheating, damage, or failure due to air entrainment and temperature changes, making it difficult to accurately detect leakage in heat medium circuits.
Innovation Solution
An air-conditioning apparatus equipped with a refrigeration cycle, a heat medium circuit, and a controller that calculates an actual temperature efficiency ratio based on inlet and outlet temperatures of the heat medium and air, determining abnormal flow rates by comparing this ratio to a set reference, allowing for precise detection of flow rate abnormalities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If heat medium leakage detection is performed based on temperature change, then leakage can be detected, but detection accuracy is low because temperature change varies with water amount
Solution Approach 1:
The patent changes the detection parameter from temperature change alone to temperature efficiency ratio, which is calculated by dividing temperature change by heat input. This parameter transformation eliminates the influence of water amount variations, enabling accurate leakage detection regardless of the quantity of heat medium present in the system.
Solution Approach 2:
The patent combines multiple detection parameters (temperature change, heat input, and their ratio) to create a composite detection metric. By integrating these multiple factors into the temperature efficiency ratio, the system achieves robust leakage detection that compensates for the limitations of single-parameter detection methods.
2Object-affected harmful factors
If heat medium is circulated in indoor space, then health safety is improved, but leakage detection becomes difficult due to lack of adverse effects on users
Solution Approach 1:
The patent replaces direct physical leakage detection methods with a thermal parameter analysis approach. By monitoring temperature efficiency ratio changes in the heat medium circuit, the system can indirectly detect leakage without relying on direct observation or complex sensing mechanisms, thus solving the detection difficulty while maintaining the use of safe heat mediums.
Solution Approach 2:
The patent introduces temperature efficiency ratio as an intermediary parameter that mediates between the heat medium circulation system and the detection system. This intermediary metric allows leakage detection to occur through thermal parameter analysis rather than direct leakage observation, enabling reliable detection while maintaining user safety through benign heat medium circulation.
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 enables accurate and efficient detection of abnormal flow rates in heat medium circuits, preventing pump damage and ensuring reliable operation by promptly identifying and addressing flow rate issues.
Implementation Method 1
at least one intermediate heat exchanger configured to exchange heat between the heat source side refrigerant and a heat medium different from the heat source side refrigerant
Implementation Method 2
at least one pump configured to circulate the heat medium for heat exchange by the intermediate heat exchanger
Implementation Method 3
a use side heat exchanger configured to exchange heat between the heat medium and air in an air-conditioning target space
Implementation Method 4
a compressor configured to compress a heat source side refrigerant
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
An air-conditioning apparatus includes a refrigeration cycle that includes one or more intermediate heat exchangers 15, connected by pipes, exchanging heat between a heat source side refrigerant and a heat medium different from the heat source side refrigerant, a heat medium circuit that includes at least one pump 21 configured to circulate the heat medium for heat exchange by the intermediate heat exchanger 15, a use side heat exchanger 26 configured to exchange heat between the heat medium and air in an air-conditioning target space, and flow switching valves 22 and 23 configured to switch between passing the heated heat medium through the use side heat exchanger 26 and passing the cooled heat medium through the use side heat exchanger and in which the pump 21, the use side heat exchanger 26, and the flow switching valves 22 and 23 are connected by pipes, and a controller 60 configured to calculate an actual temperature efficiency ratio based on a temperature at a heat medium inlet of the heat exchanger in the heat medium circuit and determine whether a flow rate of the heat medium in the heat medium circuit is abnormal based on the actual temperature efficiency ratio and a set reference temperature efficiency ratio.