Multi-type air conditioner and a method for checking operation of indoor electronic expansion valves of indoor units
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Solution Overview
Problem
Existing methods for checking the operation of electronic expansion valves in multi-type air conditioners face challenges due to variations in refrigerant pressure affecting temperature readings, making it difficult to accurately determine if the valves are operating reliably.
Innovation Solution
A multi-type air conditioner system that includes a pressure sensor to detect refrigerant pressure and temperature sensors for indoor heat exchangers, with a control section that calculates the saturation temperature and checks the operation of electronic expansion valves based on changes in refrigerant pressure and temperature differences, effectively canceling out pressure variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If temperature sensors are used to detect heat exchanger temperature changes for checking electronic expansion valve operation, then the operation can be monitored, but refrigerant pressure variations cause false temperature readings that reduce measurement accuracy
Solution Approach 1:
The patent introduces refrigerant pressure as an intermediary parameter to mediate between the electronic expansion valve operation and heat exchanger temperature. By detecting refrigerant pressure changes and using them to correct or interpret temperature readings, the system accurately determines valve operation status despite pressure-induced temperature variations.
Solution Approach 2:
The patent changes the monitoring parameters from solely temperature-based to a combined pressure and temperature approach. By detecting refrigerant pressure changes that occur when the electronic expansion valve opens or closes, and correlating these with temperature readings, the system achieves accurate valve operation detection while compensating for pressure-induced temperature measurement errors.
2Measurement precision
If refrigerant pressure is monitored to check electronic expansion valve operation, then pressure variations can be detected, but pressure changes occur naturally during valve operation making it difficult to distinguish between normal operation and faults
Solution Approach 1:
The patent merges pressure detection and temperature detection into a unified monitoring system. By combining refrigerant pressure data with heat exchanger temperature data, the system creates a more reliable determination of electronic expansion valve operation status, as the complementary information from both sensors allows accurate differentiation between normal operation and faults.
3Ease of operation
If the degree of opening of electronic expansion valve is changed during air-conditioning mode to check operation, then the valve can be tested, but temperature changes in heat exchanger are affected by refrigerant pressure variations reducing checking accuracy
Solution Approach 1:
The patent implements feedback by continuously monitoring refrigerant pressure and using this information to interpret temperature changes in the heat exchanger. When the electronic expansion valve degree of opening is changed during operation, the system detects the resulting pressure changes and uses them to correct or contextualize temperature readings, ensuring accurate assessment of valve operation despite pressure-induced temperature variations.
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 approach allows for reliable checking of electronic expansion valve operation by isolating the effect of refrigerant pressure variations, ensuring accurate detection of valve functionality.
Implementation Method 1
a pressure sensor for detecting refrigerant pressure on a low-pressure side in the outdoor unit
Implementation Method 2
temperature sensors for detecting the temperatures of the indoor heat exchangers of the indoor units
Implementation Method 3
a compressor for compressing refrigerant, a four-way switching valve, an outdoor heat exchanger
Implementation Method 4
indoor-side electronic expansion valves and are connected in parallel between the refrigerant gas pipe and the refrigerant liquid pipe
Data Source
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AI summary
Provided are a multi-type air conditioner, a method for checking the operation of indoor-side electronic expansion valves of indoor units, a computer program, and a fault diagnosis system that allow the operation of electronic expansion valves of indoor units to be reliably checked. A saturation temperature (TS) is calculated from a refrigerant pressure (PL) detected on the low-pressure side of an outdoor unit by a pressure sensor, and the operation of electronic expansion valves is checked using temperature differences (TD) between the calculated saturation temperature (TS) and the temperatures (TE) of indoor heat exchangers detected by temperature sensors. This allows the effect of variations in refrigerant pressure (PL) to be canceled so that the operation of the electronic expansion valves is reliably checked.