Indirect Heat Exchanger with Segmented Airflow Paths
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing heat exchangers that operate in both wet and dry modes lack independent control over airflow paths, leading to inefficient use of evaporative liquid and reduced effectiveness of the dry mode due to dominance by the wet side in heat transfer processes.
Innovation Solution
A heat exchanger design with multiple airflow paths that allows independent operation of each path in wet or dry modes, controlled by a logic controller that adjusts airflow and dispensing rates based on monitored parameters to optimize efficiency and conserve water.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the heat exchanger operates in wet mode to increase heat transfer efficiency, then the heat exchange efficiency is improved, but the evaporative liquid consumption increases
Solution Approach 1:
The heat exchanger is divided into multiple independent airflow paths (first airflow path, second airflow path, etc.), each capable of operating independently in wet or dry mode. This segmentation allows selective application of evaporative liquid only to paths that require it, thereby maintaining high heat exchange efficiency while reducing overall evaporative liquid consumption.
Solution Approach 2:
The system dynamically adjusts the operating mode of each airflow path based on real-time conditions. The controller can switch individual paths between wet and dry modes as needed, allowing the heat exchanger to optimize its performance and water usage dynamically rather than operating all paths in a fixed mode.
2Loss of substance
If the heat exchanger operates in dry mode to conserve evaporative liquid, then the evaporative liquid consumption is reduced, but the heat exchange efficiency decreases
Solution Approach 1:
By segmenting the heat exchanger into multiple independent airflow paths, the system can maintain high heat exchange efficiency overall by keeping some paths in wet mode while conserving water by operating other paths in dry mode, thus balancing efficiency and water conservation.
Solution Approach 2:
Different airflow paths can have different operating modes (wet or dry) based on local requirements. This allows the system to apply evaporative cooling only where and when it is most effective, rather than uniformly across all paths, thereby maintaining efficiency while reducing water consumption.
3Productivity
If multiple airflow paths operate simultaneously in wet mode to maximize heat exchange, then the heat exchange capacity is increased, but the water usage increases proportionally
Solution Approach 1:
The heat exchanger is segmented into multiple independent airflow paths that can be selectively operated in wet or dry mode. This allows the system to distribute the heat exchange load across multiple paths, using evaporative cooling only on a subset of paths at any given time, thereby maintaining high overall heat exchange capacity while significantly reducing total water usage compared to operating all paths in wet mode.
Solution Approach 2:
The system dynamically adjusts which airflow paths operate in wet mode and which operate in dry mode based on real-time heat exchange requirements and water availability. This dynamic allocation allows the system to maintain high heat exchange capacity when needed while conserving water during periods of lower demand or water scarcity.
4Productivity
If the airflow rate is increased to enhance heat transfer, then the heat exchange efficiency is improved, but the energy consumption increases
Solution Approach 1:
The system dynamically adjusts the airflow rate in each path based on its operating mode and heat exchange requirements. When a path operates in wet mode, a lower airflow rate may suffice due to the enhanced heat transfer from evaporation. When operating in dry mode, the airflow rate can be optimized independently. This dynamic adjustment allows the system to maintain high heat exchange efficiency while minimizing the energy consumption of airflow generators.
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 design enables efficient use of evaporative liquid by allowing independent control of airflow and dispensing modes, ensuring the dry path contributes effectively to heat exchange while minimizing water usage, thereby optimizing energy and water savings.
Implementation Method 1
This invokes the principals of evaporation to further increase the rate of heat transfer from the fluid
Implementation Method 2
Air, typically cool air relative to the indirect heat exchanger, passes over the coil, which uses convection principals to facilitate the indirect exchange of heat between the fluid and the air
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An indirect heat exchanger has two airflow paths and an airflow generator to draw air through the airflow paths. A fluid conduit passes through the heat exchanger such that a cooling region is positioned within each of the flow paths. A dispenser is positioned to dispense evaporative liquid on one of the cooling regions. The dispenser operates in a wet mode and a dry mode. A controller regulates airflow through the first flow path and the second flow path, and also controls the operation of the dispenser. In this way, the controller may operate the airflow paths independently such that the airflow through a flow path operating in the dry mode is greater than that of the flow path operating in the wet mode.