Two Phase Distributor Evaporator Manifold Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Uniform distribution of two-phase fluid flow in heat exchangers, such as mini-channel, microchannel, and plate-fin exchangers, is challenging due to phase separation under different operating conditions, particularly in refrigerant systems where the flow is distributed among many layers and small ports.
Innovation Solution
A heat exchanger design featuring a manifold with a distributor assembly that includes axial and radial flow channels, sized to maintain fluid velocity and prevent separation, along with a nozzle to create a homogeneous distribution, ensuring equal fluid supply to each passage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a closed-end tube distributor with side holes is used to distribute two-phase fluid among many layers and small ports, then distribution capability is improved, but phase separation occurs under different operating conditions
Solution Approach 1:
The distributor is segmented into multiple axial flow channels (e.g., three channels) with radial connecting channels distributed along the axial direction. This segmentation allows the two-phase fluid to be divided into multiple streams, each maintaining sufficient velocity to prevent phase separation, while still distributing to multiple layers and ports.
Solution Approach 2:
The distributor transitions from a simple side-hole configuration to a three-dimensional network of axial and radial channels. The axial channels extend along the length of the distributor, while radial channels connect to flow passages at different radial positions, creating a multi-dimensional distribution network that maintains velocity and prevents separation.
2Productivity
If flow is distributed among many layers and small ports, then heat exchanger performance is improved, but uniform distribution of two-phase fluid flow becomes difficult to achieve
Solution Approach 1:
Different regions of the distributor have specialized functions: axial flow channels maintain high velocity to prevent separation, radial connecting channels provide local distribution to specific layers, and the configuration of channels is optimized for different azimuthal angles to ensure uniform distribution to all ports.
Solution Approach 2:
The distributor design changes key flow parameters by maintaining high fluid velocity through appropriately sized axial and radial channels. The channel dimensions are specifically designed to preserve the two-phase fluid's kinetic energy and prevent phase separation while distributing to numerous small ports.
3Stability of the object's composition
If distributor channels are sized to maintain fluid velocity and limit separation, then phase separation is reduced, but device complexity increases
Solution Approach 1:
The distributor employs a nested channel structure where radial connecting channels branch off from axial flow channels, which in turn are contained within the distributor body. This nested arrangement efficiently packs multiple flow paths within a compact volume, reducing overall device complexity while maintaining the velocity necessary to prevent phase separation.
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 solution achieves improved fluid distribution, reducing phase separation and enhancing the performance and efficiency of refrigerant systems by maintaining a uniform flow across a wider range of conditions, leading to increased coefficient of performance and reduced power consumption.
Implementation Method 1
Uniform distribution of two-phase fluid flow (liquid and gas) inside heat exchangers is difficult to achieve
Implementation Method 2
such distributors may not prevent separation of the two-phase fluid under different operating conditions
Implementation Method 3
The nozzle may include a constriction configured to produce a pressure drop in the fluid
Data Source
Figure 1
Figure 2
Figure 2a~2c
AI summary
A heat exchanger is provided including a plurality of parallel stacked plates defining at least one flow passage there between. A manifold having a generally hollow interior is arranged adjacent the plurality of parallel plates. An opening is disposed between adjacent stacked plates. The opening is configured to fluidly couple the hollow interior of the manifold and the at least one flow passage. A distributor assembly including an insert is disposed at least partially within the hollow interior of the manifold. The insert includes a plurality of circumferentially spaced axial flow channels and a plurality of radial connecting channels arranged in fluid communication with the axial flow channels. The radial flow channels are fluidly coupled to the at least one flow passage via the opening.