Falling Film Evaporator Support Sheets for Uniform Vapor Flow

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Falling film evaporators in HVAC systems have a large vertical gap between support sheets and baffles, which increases the height of the evaporator and reduces the uniformity of upward vapor flow, leading to suboptimal thermal energy transfer.

Innovation Solution

Incorporating support sheets with vapor flow passages along the length of evaporator tubes to allow vapor refrigerant flow, eliminating the need for a large gap between the baffle and support sheets, thereby reducing the evaporator height and enhancing vapor flow uniformity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large vertical gap is left between support sheets and baffle to compensate for vapor flow blockage, then vapor flow can be redistributed around the baffle, but the evaporator height increases undesirably

Engineering Contradiction:

Improvevapor flow redistributionVSAvoidevaporator height

Core Design Contradiction:

ReliabilityVSLength of stationary object

Solution Approach 1:

The support sheet is divided into multiple sections: a first support sheet portion that supports the tube bundle, a second support sheet portion that extends upward to abut the baffle, and vapor flow passages between them. This segmentation allows the support structure to both support tubes and facilitate vapor flow without requiring excessive height.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The second support sheet portion acts as an intermediary element between the baffle and the tube bundle, providing a pathway for vapor flow while maintaining structural support. This intermediary structure eliminates the need for a large gap by creating a controlled flow path through the support sheet itself.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Length of stationary object

If support sheets are positioned close to the baffle to reduce evaporator height, then height is minimized, but upward vapor flow is blocked in the section between support sheets

Engineering Contradiction:

Improveevaporator heightVSAvoidvapor flow uniformity

Core Design Contradiction:

Length of stationary objectVSReliability

Solution Approach 1:

The support sheet incorporates vapor flow passages that create a porous-like structure, allowing vapor to pass through the support sheet itself. This enables the support sheet to be positioned close to the baffle while maintaining vapor flow uniformity through the passages rather than around the baffle.

Inventive Principle:

Principle #31Porous materials

3Ease of manufacture

If traditional support sheets without vapor flow passages are used, then manufacturing is simpler, but vapor flow uniformity and thermal energy transfer are reduced

Engineering Contradiction:

Improvesupport sheet fabricationVSAvoidthermal energy transfer efficiency

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The support sheet is segmented into functional zones with integrated vapor flow passages. While this adds some manufacturing complexity, it significantly improves thermal energy transfer efficiency by ensuring uniform vapor flow distribution across the evaporator surface.

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 configuration improves the uniformity of vapor flow and reduces the overall height of the evaporator, enhancing thermal energy transfer efficiency and optimizing the design of falling film evaporators in HVAC systems.

Implementation Method 1

the one or more support sheets including one or more vapor flow passages to allow flow of vapor refrigerant along a length of the evaporator

Methodology Applied

Scientific EffectVapor flow:

Implementation Method 2

HVAC systems, such as chillers, use an evaporator to facilitate a thermal energy exchange between a refrigerant in the evaporator and a medium flowing in a number of evaporator tubes

Methodology Applied

Scientific EffectThermal energy exchange: Heat Exchanger

Implementation Method 3

In a falling film evaporator, bundles or groups of evaporator tubes are positioned typically below a distribution manifold from which refrigerant is urged, forming a 'falling film' on the evaporator tubes

Methodology Applied

Scientific EffectFalling film:

Data Source

PatentUS9915452B2Support sheet arrangement for falling film evaporator

Publication Date: 2018.03.13 CARRIER CORP

AI summary

A falling film evaporator for a heating ventilation and air conditioning (HVAC) system includes an evaporator housing and a plurality of evaporator tubes located in the evaporator housing and arranged into one or more tube bundles. A volume of thermal energy transfer medium is flowed through the plurality of evaporator tubes. One or more support sheets located along a length of the plurality of evaporator tubes to position and support the plurality of evaporator tubes in the housing, the one or more support sheets including one or more vapor flow passages to allow flow of vapor refrigerant along a length of the evaporator.