Multi-split system and method for controlling heating throttling element thereof

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Solution Overview

Problem

Multi-split air conditioning systems face challenges in maintaining energy efficiency and user experience, particularly during partial load heating, due to inadequate control of the heating throttling element, which affects refrigerant flow and condensation temperature.

Innovation Solution

The method involves adjusting the opening of the heating throttling element based on the pressure difference between high and intermediate pressures in the shunt device, using sensors to control the compressor and calculate target pressure differences, ensuring stable operation and optimal refrigerant flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the opening of the heating throttling element is increased to improve refrigerant flow and heating capacity, then heating performance is improved, but liquid discharge requirements may not be met and system stability deteriorates

Engineering Contradiction:
Improveheating capacityVSAvoidsystem stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements a feedback control mechanism where the opening degree of the heating throttling element is dynamically adjusted based on real-time detection of high-pressure and intermediate-pressure values. The control method calculates the pressure difference and compares it with a preset threshold to automatically adjust the throttling element opening, ensuring the system maintains optimal operation within stable parameters while meeting heating capacity requirements.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent transitions from a static throttling element opening to a dynamic adjustment mechanism. The opening degree of the heating throttling element is no longer fixed but is continuously adjusted based on system operating conditions (pressure difference), allowing the system to adapt to varying load conditions and maintain both heating capacity and stability across different operating scenarios.

Inventive Principle:
Principle #15Dynamics

2Productivity

If the opening of the heating throttling element is optimized for high load conditions, then heating capacity is improved, but performance during partial load heating deteriorates

Engineering Contradiction:
Improveheating capacityVSAvoidpartial load performance
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic adjustment of the heating throttling element opening based on real-time pressure difference detection. This allows the system to adapt to different load conditions automatically - during partial load, the pressure difference changes trigger appropriate opening adjustments that optimize refrigerant flow and maintain heating capacity, whereas a fixed opening would be suboptimal for varying conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operating parameters (opening degree of heating throttling element) based on system conditions. By monitoring pressure difference and adjusting the throttling element opening accordingly, the system optimizes refrigerant flow characteristics for different load conditions, improving adaptability across the full operating range from partial to full load.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If the heating throttling element opening is increased to meet liquid discharge requirements, then refrigerant flow is improved, but condensation temperature control and energy efficiency deteriorate

Engineering Contradiction:
Improverefrigerant flowVSAvoidcondensation temperature
Core Design Contradiction:
Quantity of substanceVSTemperature

Solution Approach 1:

The patent uses feedback control where the opening of the heating throttling element is adjusted based on detected pressure values. This closed-loop control ensures that refrigerant flow is optimized for liquid discharge while simultaneously maintaining proper condensation temperature, as the system responds to actual operating conditions rather than using a fixed opening that cannot balance both requirements.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent dynamically changes the throttling element opening parameter based on system conditions. By adjusting this parameter in response to pressure difference measurements, the system optimizes both refrigerant flow quantity and condensation temperature simultaneously, achieving a balance that fixed-parameter systems cannot accomplish.

Inventive Principle:
Principle #35Parameter changes

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 enhances energy efficiency and user experience by maintaining optimal refrigerant flow and condensation temperature, meeting liquid discharge requirements and improving system performance during heating, especially under partial load conditions.

Implementation Method 1

the opening of the heating throttling element is adjusted by the pressure difference between the high pressure and the intermediate pressure of the shunt device

Methodology Applied
Scientific EffectPressure difference: Pressure Gradient

Implementation Method 2

it expands into the low-pressure gas through the electronic expansion valve

Methodology Applied
Scientific EffectThrottling: Valve

Implementation Method 3

after it releases heat in the heating indoor unit

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 4

the condensation temperature of the heating indoor unit will be adjusted

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentEP3467390B1Multi-split system and method for controlling heating throttling element thereof
Publication Date: 2021.02.17 GD MIDEA HEATING & VENTILATING EQUIP CO LTD
  • EP3467390B1 patent drawingFigure 1
  • EP3467390B1 patent drawingFigure 2
  • EP3467390B1 patent drawingFigure 3

AI summary

A method for controlling a heating throttling element (35) in a multi-split system comprises: obtaining a target gas discharge pressure of a compressor, or a saturation temperature corresponding to the target gas discharge pressure (S1); controlling the compressor according to the target gas discharge pressure or the saturation temperature corresponding to the target gas discharge pressure to enable the compressor to operate stably, obtaining a high pressure and an intermediate pressure of a bypass device (30) after operation of the compressor becomes stable, and calculating a pressure difference between the high pressure and an intermediate pressure (S2); and obtaining a target pressure difference between the high pressure and an intermediate pressure of the bypass device (30), and adjusting an opening degree of the heating throttling element (35) according to the pressure difference and the target pressure difference. A multi-split system applying the method for controlling the heating throttling element is also disclosed.