Evaporator Refrigerant Distributor for Uniform Two-Phase Flow
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Solution Overview
Problem
Conventional distributors in turbo refrigerating machines face challenges in uniformly distributing refrigerant along heat transfer pipes due to high refrigerant velocity and inefficient separation of gaseous and liquid phases, leading to non-uniform dynamic pressure and reduced heat exchange performance.
Innovation Solution
A distributor with an integrated gas-liquid separator and porous plates that control dynamic pressures and separate refrigerant phases, ensuring uniform distribution of liquid refrigerant to the heat transfer pipe, and a system of refrigerant dropping devices that guide the refrigerant to the pipe with decreasing sectional area to enhance distribution efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If refrigerant velocity is increased to improve heat exchange efficiency, then heat transfer performance is improved, but uniform distribution of refrigerant along the heat transfer pipe deteriorates
Solution Approach 1:
The distributor is divided into multiple distribution holes arranged in different patterns (first pattern and second pattern) to segment the refrigerant flow into multiple streams. This segmentation allows the high-velocity refrigerant to be distributed uniformly along the heat transfer pipe length, preventing concentration in single areas while maintaining overall high flow rates for efficient heat exchange.
Solution Approach 2:
Different regions of the distributor are designed with different hole patterns and orientations. The first distribution holes are arranged in a first pattern while the second distribution holes are arranged in a second pattern, creating local variations in flow distribution. This local quality approach ensures that each section of the heat transfer pipe receives appropriate refrigerant distribution even at high velocities.
2Device complexity
If conventional distributor design is used, then device complexity is low, but separation of gaseous and liquid refrigerant phases deteriorates
Solution Approach 1:
The distributor is positioned to receive refrigerant from the gas-liquid separator before the refrigerant enters the heat transfer pipe. This preliminary action of distributing refrigerant immediately after phase separation ensures that liquid and gaseous phases are properly separated and directed, preventing mixture issues downstream while maintaining a relatively simple overall device structure.
Solution Approach 2:
The distributor acts as an intermediary component between the gas-liquid separator and the heat transfer pipe. It receives the separated refrigerant phases, controls their distribution through specifically arranged holes, and delivers them to appropriate locations, thereby mediating the transition from phase separation to heat exchange while maintaining structural simplicity.
3Ease of manufacture
If distributor holes are arranged in single pattern, then manufacturing is simple, but refrigerant distribution uniformity deteriorates
Solution Approach 1:
The distributor employs asymmetric hole arrangements with at least one distribution hole having an orientation different from others. The first and second distribution holes are oriented at different angles relative to the heat transfer pipe, creating asymmetric flow patterns that promote uniform refrigerant distribution along the pipe length while maintaining manufacturing feasibility through systematic asymmetric design.
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 effectively controls two-phase flow, prevents liquid refrigerant from entering the compressor, and improves heat exchange efficiency by ensuring uniform refrigerant distribution across the heat transfer pipe, reducing dry spots and enhancing overall performance.
Implementation Method 1
a gas-liquid separator unit provided within the shell, which separates gaseous refrigerant and liquid refrigerant from a refrigerant mixture introduced into the evaporator
Implementation Method 2
a distributor unit formed under the gas-liquid separator unit and provided with a plurality of refrigerant dropping units so as to uniformly distribute the liquid refrigerant introduced from the gas-liquid separator unit
Data Source
AI summary
A distributor and an evaporator having the same are provided. The distributor may include a first refrigerant distributor provided with a plurality of through holes formed in a first direction, and a plurality of refrigerant dropping devices that guide refrigerant, dropped from the first refrigerant distributor through the plurality of through holes, to a heat transfer pipe, and having a sectional area of flow surfaces thereof that decreases in a flow direction of the refrigerant.