Throttling device and refrigeration system having the same

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Solution Overview

Problem

Conventional throttling devices in refrigeration systems are prone to surge in centrifugal compressors, especially during conditions of small capacity and high lift, leading to increased noise, vibration, and power consumption, and potential damage to compressor blades.

Innovation Solution

A throttling device with a limit piece that can move up and down along a chute, adjusting the minimum flow area of the orifice plate, and an actuator that moves the limit piece based on preset surge conditions to prevent compressor surge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a conventional throttling device with float valve and orifice plate is used, then the device structure is simple and cost is reduced, but the centrifugal compressor is prone to surge under small capacity and high lift conditions

Engineering Contradiction:
Improvethrottling device structure simplicityVSAvoidcompressor surge prevention
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies the dynamics principle by making the orifice plate movable rather than fixed. The orifice plate can rotate around a pivot point to adjust the flow area dynamically based on system conditions. This dynamic adjustment capability allows the throttling device to adapt to varying operating conditions, particularly preventing compressor surge during part-load operation while maintaining structural simplicity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by varying the flow area of the orifice plate through rotation. The flow area parameter is changed by adjusting the angular position of the orifice plate, which modifies the refrigerant flow characteristics. This parameter adjustment prevents compressor surge by ensuring adequate minimum flow while maintaining system efficiency

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the orifice plate opening is reduced to control refrigerant flow, then refrigerant flow is controlled, but the centrifugal compressor experiences low flow and high pressure ratio leading to surge

Engineering Contradiction:
Improverefrigerant flow controlVSAvoidcompressor surge prevention
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent changes the geometric parameter of the orifice plate by rotating it to different angular positions. This parameter change allows continuous adjustment of the flow area, enabling precise control of refrigerant flow while maintaining sufficient minimum flow to prevent compressor surge during part-load conditions

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If the orifice plate is fixed, then the device structure is simple, but the refrigeration system cannot adapt to varying operating conditions especially small capacity and high lift

Engineering Contradiction:
Improvethrottling device structureVSAvoidoperating condition adaptability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent transforms the static orifice plate into a dynamic component that can rotate to adjust flow area. This dynamic capability enables the throttling device to adapt to varying operating conditions including part-load and high-lift scenarios, while the rotation mechanism around a pivot point keeps the overall device structure relatively simple

Inventive Principle:
Principle #15Dynamics

4Productivity

If centrifugal compressor operates under small capacity and high lift conditions, then system capacity is reduced, but surge occurs leading to increased noise, vibration and power consumption

Engineering Contradiction:
Improvesystem capacityVSAvoidnoise, vibration and power consumption
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent adjusts the flow area parameter of the orifice plate by rotation to maintain adequate minimum flow even during part-load operation. This parameter adjustment prevents compressor surge, thereby reducing harmful effects such as noise, vibration, and excessive power consumption that would otherwise occur during small capacity and high lift conditions

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

The throttling device effectively suppresses surge in centrifugal compressors by ensuring a stable gas supply, improving compressor efficiency and stability, reducing noise and vibration, and preventing damage to compressor blades.

Implementation Method 1

the floating balls float up and down with the liquid level of the liquid refrigerant

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 2

the throttling device is an important component, which mainly changes the coolant (also known as 'refrigerant') passing through the throttling device from high-temperature and high-pressure liquid coolant to low-temperature and low-pressure liquid coolant

Methodology Applied
Scientific EffectThrottling: Pressure Drop

Data Source

PatentEP4242557B1Throttling device and refrigeration system having the same
Publication Date: 2025.01.22 CARRIER CORP
  • EP4242557B1 patent drawingFigure 1~2
  • EP4242557B1 patent drawingFigure 3~4

AI summary

The present invention relates to a throttling device (10), comprising: a tank for accommodating liquid refrigerant, with an orifice plate (16) arranged at an outlet of the tank; a floating ball (11) capable of floating on a liquid surface of the refrigerant; a pivot rod (13) pivotally fixed on the tank through a pivot shaft; a connecting rod (12), with one end thereof fixedly connected with the floating ball (11), and the other end thereof fixedly connected with the pivot rod (13); a valve plate (14) fixed on the pivot rod (13) and located near an orifice of the orifice plate (16), wherein the valve plate (14) is capable of adjusting a flow area of the orifice under the action of the pivot rod (13); and a limit piece (15) located above the valve plate (14) and being movable to limit the valve plate (14). The present invention further provides a refrigeration system equipped with the throttling device (10). The throttling device (10) according to the present invention can effectively reduce surge of a centrifugal compressor.