Electronic Expansion Valve Sleeve Structure Against Internal Leakage
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Solution Overview
Problem
Conventional electronic expansion valves experience internal leakage due to eccentricity of the valve core seat caused by high-pressure refrigerant flow, leading to reduced system efficiency and reliability.
Innovation Solution
The electronic expansion valve design incorporates a sleeve within the main valve cavity, where the valve core seat is axially movable and the valve needle component extends into the sleeve to open and close the valve core valve port, with a sleeve flow passage allowing communication between the sleeve and main valve cavity, reducing pressure impact on the valve core seat and preventing eccentricity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the electronic expansion valve is placed far from the evaporator to reduce heat loss, then heat loss is reduced, but the refrigerant is apt to be gasified and the utilization rate of the evaporator is reduced
Solution Approach 1:
A gas-liquid separator is introduced as an intermediary component between the electronic expansion valve and the evaporator. The separator receives refrigerant from the expansion valve and separates gas from liquid phases, then delivers liquid refrigerant to the evaporator. This mediator prevents gasified refrigerant from entering the evaporator, maintaining high utilization rate while allowing the expansion valve to be positioned optimally for heat loss reduction
2Stress or pressure
If the electronic expansion valve is fully opened to reduce throttling effect, then pressure reduction is minimized, but the valve core seat becomes eccentric and internal leakage occurs
Solution Approach 1:
A balance hole is provided in the valve core seat that communicates with the high-pressure side and low-pressure side. This balance hole equalizes the pressure distribution on both sides of the valve core seat, creating a counterbalancing effect that prevents the seat from becoming eccentric during operation, thereby maintaining sealing performance while allowing the valve to remain fully open and minimize throttling losses
3Reliability
If two electronic expansion valves are employed with one-way valves in parallel to improve system efficiency, then system efficiency is improved, but the number of parts and solder joints increases
Solution Approach 1:
The electronic expansion valve is designed with multi-functionality by integrating a gas-liquid separator and a balance hole mechanism into a single device. The valve can selectively regulate flow to different evaporators while also separating gas-liquid phases and maintaining pressure balance. This universal design achieves the system efficiency of multiple valves without requiring separate one-way valves and complex parallel configurations
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 design significantly reduces internal leakage and ensures reliable operation by mitigating the impact of high-pressure refrigerant on the valve core seat, enhancing the sealing performance and system efficiency.
Implementation Method 1
the valve core seat moves downward under the action of a pressure difference of the refrigerant, thereby closing the main valve port
Implementation Method 2
enters into an indoor heat exchanger to be evaporated, so as to absorb heat to realize the refrigerating function
Implementation Method 3
an outdoor heat exchanger (releasing heat by condensation)
Data Source
AI summary
An electronic expansion valve is provided, a sleeve is fixed in a main valve cavity of the electronic expansion valve, and a valve core seat is axially movably provided in the sleeve; a circumferential side wall of the sleeve is provided with a sleeve flow passage, and a circumferential side wall of the valve core seat is provided with a valve core seat side hole; and when the refrigerant flows forward, the valve core seat closes the main valve port to disconnect a communication between the sleeve flow passage and the valve core seat side hole, and the refrigerant flows to the valve core valve port through the sleeve flow passage; and when the refrigerant flows reversely, the valve core seat moves upward to open the main valve port to communicate the valve core seat side hole with the sleeve flow passage.