Electronic Expansion Valve Control With Outdoor Temperature Compensation
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Solution Overview
Problem
Existing air conditioning systems face challenges in accurately controlling the electronic expansion valve due to variations in outdoor environment temperature, leading to inefficiencies in energy efficiency ratios, as the desired output temperature is often determined solely by compressor frequency without consideration for real-time outdoor conditions.
Innovation Solution
A control method that adjusts the target exhaust temperature based on both real-time compressor running frequency and outdoor environment temperature, using a PID algorithm with adaptive integral coefficients to optimize the opening amount of the electronic expansion valve, ensuring more precise control and improved energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the desired output temperature is determined only by compressor frequency, then the control system is simple, but the control accuracy deteriorates due to outdoor temperature variations
Solution Approach 1:
The patent applies dynamics by making the desired output temperature a dynamic value that changes with outdoor environment temperature. Instead of a fixed temperature determined only by compressor frequency, the system dynamically adjusts the target temperature based on real-time outdoor conditions, allowing the control system to adapt to varying environmental conditions while maintaining reasonable complexity
Solution Approach 2:
The patent implements feedback by incorporating outdoor environment temperature as an input parameter that influences the desired output temperature calculation. The system continuously monitors outdoor temperature and uses this feedback to adjust the target exhaust temperature, thereby improving control accuracy without requiring a completely complex control architecture
2Ease of manufacture
If the PID controller constants are kept constant, then the control system is simple to implement, but the control performance deteriorates in response to operating condition variations
Solution Approach 1:
The patent applies dynamics by transitioning from static PID constants to dynamic adaptive constants. The proportional, integral, and differential coefficients are no longer fixed values but are adjusted based on operating conditions such as outdoor temperature and compressor frequency, enabling the system to adapt to different operating scenarios while maintaining implementation feasibility through structured adjustment rules
3Speed
If the electronic expansion valve opening is controlled using inaccurate desired output temperature, then the control response is fast, but the energy efficiency ratio deteriorates
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing the relationship between outdoor environment temperature and the compensation amount for desired output temperature in a lookup table or database. This allows the system to quickly retrieve the appropriate temperature adjustment based on current outdoor conditions, maintaining fast control response while improving energy efficiency through more accurate target temperature determination
Data Source
AI summary
Provided is a control method for an electronic expansion valve in air conditioner comprises: obtaining a real-time running frequency of compressor, a real-time exhaust temperature and a real-time outdoor environment temperature as the compressor running; retrieving a target exhaust temperature according to the real-time running frequency in a preset relation in which each available target exhaust temperature is paired with a single real-time running frequency, wherein the target exhaust temperature retrieved being defined as a first target exhaust temperature; defining a sum of the first target exhaust temperature and a set compensation temperature as a second target exhaust temperature, wherein the set compensation temperature is determined by the real-time outdoor environment temperature; and performing a PID control on opening amount of the electronic expansion valve based on a deviation that is a difference between the real-time exhaust temperature and the second target exhaust temperature. The method achieves an accurate and stable control on opening amount of electronic expansion valve in air conditioner.