Air conditioner
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional air conditioner control methods fail to adequately curb the deterioration of compressor durability during heating operations in extremely low temperature environments, where high compression ratios lead to increased wear and reduced durability.
Innovation Solution
An air conditioner system with a control unit that adjusts the expansion valve throttle based on discharge and suction temperatures, switching between discharge temperature control and superheat control modes, and optionally adjusting compressor operating frequency, to manage the discharge temperature and reduce compressor load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If discharge temperature control is performed using conventional fixed threshold methods, then control simplicity is maintained, but compressor durability deteriorates in extremely low temperature environments
Solution Approach 1:
The patent applies dynamics by making the threshold temperature dynamic rather than fixed. The threshold temperature is adjusted based on the saturated vapor temperature, which varies with outdoor conditions. This allows the control system to adapt to extremely low temperature environments while maintaining reasonable control complexity, thereby improving compressor durability without excessive system complexity.
Solution Approach 2:
The patent changes the parameter of threshold temperature based on the saturated vapor temperature. By establishing a relationship where the threshold temperature varies with the saturated vapor temperature (e.g., threshold = saturated vapor temperature + predetermined value), the system optimizes discharge temperature control for different operating conditions, preventing compressor durability deterioration in extreme cold while maintaining control simplicity.
2Ease of operation
If the expansion valve throttle is adjusted to maintain constant superheat, then refrigerant temperature control is simplified, but compressor load is not sufficiently reduced in high compression ratio conditions
Solution Approach 1:
The patent changes the control parameter from constant superheat maintenance to discharge temperature control with a dynamic threshold. By controlling the discharge temperature to be below the dynamic threshold (saturated vapor temperature + predetermined value), the system reduces compressor load in high compression ratio conditions while maintaining ease of operation through temperature-based control.
Solution Approach 2:
The patent implements feedback control by continuously monitoring the discharge temperature and comparing it with the dynamic threshold temperature. The expansion valve throttle is adjusted based on this feedback to maintain discharge temperature below the threshold, thereby reducing compressor load and improving durability while maintaining simple temperature-based control logic.
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
The system effectively reduces the load on the compressor in low temperature environments, enhancing its durability and extending its lifespan by dynamically adjusting control modes and frequencies based on refrigerant conditions.
Implementation Method 1
a discharge temperature sensor that detects a discharge temperature of a refrigerant discharged from a compressor
Implementation Method 2
a suction temperature sensor that detects a suction temperature of a refrigerant sucked by the compressor
Implementation Method 3
a saturated vapor temperature sensor that detects a saturated vapor temperature of the refrigerant
Implementation Method 4
adjusting a throttle of the expansion valve so that the discharge temperature of the compressor becomes a predetermined target value
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
An air conditioner of an embodiment is an air conditioner with an outdoor unit and an indoor unit and includes a control unit. The control unit executes a first control process of adjusting a throttle of an expansion valve so that a discharge temperature of a compressor, which is included in the outdoor unit, becomes a predetermined target value when the discharge temperature of a refrigerant discharged by the compressor is equal to or higher than a threshold temperature and executes a second control process of adjusting the throttle of the expansion valve to maintain super heat of the refrigerant at a constant value when the discharge temperature of the compressor is lower than the threshold temperature. The control unit changes the threshold temperature according to a saturated vapor temperature of the refrigerant.