Refrigeration cycle apparatus
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Solution Overview
Problem
Existing refrigeration cycle apparatuses cannot determine which between the pressure sensor and the temperature sensor is abnormal, leading to potential misidentification and inefficient maintenance.
Innovation Solution
Incorporating a high-pressure sensor and temperature sensors within the refrigeration cycle apparatus, with a controller that determines sensor abnormalities by comparing detected temperatures with calculated saturated liquid and gas temperatures, allowing for precise identification of pressure sensor issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the evaporating pressure is determined based on refrigerant temperature detected by a temperature sensor and compared with refrigerant pressure detected by a pressure sensor, then it is possible to detect that at least one sensor is abnormal, but it is not possible to determine which specific sensor is abnormal
Solution Approach 1:
The patent segments the sensor abnormality detection process into two distinct detection methods: one for detecting whether a sensor is abnormal, and another for identifying which specific sensor is abnormal. This is achieved by dividing the detection logic into multiple determination steps (S101-S106) that separately evaluate temperature sensor abnormalities and pressure sensor abnormalities using different comparison criteria involving saturated liquid temperature and saturated gas temperature.
Solution Approach 2:
The patent introduces an intermediary approach by using saturation temperature calculations as a reference standard. By calculating both saturated liquid temperature and saturated gas temperature from the detected pressure, and comparing these with the detected temperature, the system creates an intermediary reference frame that enables independent verification of each sensor's accuracy without directly comparing the two sensors against each other.
2Reliability
If existing sensor detection methods are used, then sensor abnormalities can be detected, but maintenance time increases due to inability to identify the specific abnormal sensor
Solution Approach 1:
The patent applies preliminary action by pre-calculating both saturated liquid temperature and saturated gas temperature from the detected pressure before performing temperature comparisons. This preliminary calculation step prepares the reference values in advance, enabling rapid determination of sensor abnormalities without requiring time-consuming iterative calculations during the actual detection process.
3Reliability
If pressure sensor abnormalities are not accurately identified, then erroneous high-pressure control may occur, but adding complex detection systems increases device complexity
Solution Approach 1:
The system performs self-service by using its own existing sensors and calculations to verify sensor accuracy. The controller uses the pressure sensor reading to calculate saturation temperatures, then compares these calculated temperatures with the temperature sensor reading to self-verify the pressure sensor's accuracy, eliminating the need for external reference equipment or complex additional detection systems.
Data Source
AI summary
A refrigeration cycle apparatus includes: a refrigerant circuit in which a compressor, a condenser, an expansion device, and an evaporator are connected by pipes, and refrigerant circulates; a high-pressure sensor that detects a pressure of the refrigerant on a discharge side of the compressor; a first temperature sensor that detects a temperature of the refrigerant on an outlet side of the condenser; and a controller that determines that the high-pressure sensor is abnormal, when the compressor is in operation and the temperature detected by the first temperature sensor is higher than a saturated liquid temperature or a saturated gas temperature that is calculated from the pressure detected by the high-pressure sensor.