Multi-Ejector Arrangement with Common Actuator for Mass Flow Control

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Solution Overview

Problem

Refrigeration systems face challenges in controlling the mass flow of fluid through ejectors while maintaining a simple construction, as existing solutions complicate the design and increase costs when trying to adjust the fluid output according to system requirements.

Innovation Solution

A common actuator is used to control the opening of individual motive inlets of multiple ejectors, allowing for gradual control of mass flow, with optional check valves to prevent reverse fluid flow and a compact cylindrical housing arrangement for efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If several ejectors are used in parallel to increase fluid capacity, then the total amount of fluid provided at the outlet is improved, but the device complexity increases due to the need for individual control means for each ejector

Engineering Contradiction:
Improvefluid capacityVSAvoidcontrol means complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent combines multiple individual control functions into a single common actuator that controls all ejectors simultaneously. This merging of control functions reduces device complexity while maintaining the ability to adjust the total fluid capacity of multiple parallel ejectors.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The common actuator serves as a universal control device that can adjust all ejectors in the parallel arrangement. This multi-functional actuator replaces multiple individual control mechanisms, simplifying the overall system while preserving full control capability over the total fluid capacity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of operation

If individual control means are provided for each ejector to adjust opening degree, then the control precision of mass flow is improved, but the manufacturing costs increase

Engineering Contradiction:
Improvemass flow controlVSAvoidconstruction cost
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The patent merges multiple individual control mechanisms into a single common actuator, reducing manufacturing costs while maintaining the capability to precisely control the mass flow through simultaneous adjustment of all ejectors.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If a common actuator controls all ejectors simultaneously, then the device complexity is reduced, but the control granularity of mass flow decreases

Engineering Contradiction:
Improveactuator arrangementVSAvoidmass flow control granularity
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The common actuator is designed with multiple separate engagement points that can interact with valve elements of different ejectors at different positions. This segmentation within the unified actuator allows for graduated control of mass flow by engaging different numbers or combinations of ejectors based on system requirements.

Inventive Principle:
Principle #1Segmentation

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 solution enables precise control of fluid mass flow from 0% to 100% while keeping the construction simple, allowing for proportional control and efficient operation even with varying refrigerant conditions, such as vapor and liquid mixtures during colder conditions.

Implementation Method 1

a common actuator for engaging and displacing the valve elements to open the individual motive inlets of the ejectors

Methodology Applied
Scientific EffectMechanical displacement: Displacement

Implementation Method 2

Ejectors (sometimes also called injectors) to this end use the Venturi effect to increase the pressure coming from the suction inlet by providing a high pressure motive fluid supplied by the motive inlet

Methodology Applied
Scientific EffectVenturi effect: Venturi Effect

Implementation Method 3

each ejector is provided with a check valve or non-return valve at the suction inlet. Such a check valve or non-return valve may for example be a completely pressure controlled ball-valve

Methodology Applied
Scientific EffectPressure control: Pressure Gradient

Data Source

PatentEP3109568B1Ejector arrangement
Publication Date: 2017.11.01 DANFOSS AS
  • EP3109568B1 patent drawingFigure 1
  • EP3109568B1 patent drawingFigure 2
  • EP3109568B1 patent drawingFigure 3

AI summary

The invention relates to an ejector arrangement (1, 40) comprising a housing (11) and at least two ejectors (2, 3, 41, 42) arranged in said housing (11) along a common axis (13). Each ejector (2, 3, 41, 42) has a motive inlet (4, 5), a suction inlet (6, 7), an outlet (8, 9) and a valve element (23, 24, 43, 44). The task of the invention is to provide an ejector arrangement that allows for a good control of the mass flow of fluid through the ejector arrangement while keeping the construction simple. According to the invention the above task is solved in that the ejector arrangement (1, 40) comprises a common actuator (25, 55), that is arranged to engage at least two of the valve elements (23, 24, 43, 44) to open the motive inlets (4, 5).