Method and apparatus for reduction of condensate re-evaporation during cooling part-load duty cycling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
During HVAC system ventilation, condensed moisture on evaporators re-evaporates, increasing relative humidity and the moisture load for the system, which is inefficient and requires more energy for dehumidification.
Innovation Solution
An apparatus and method involving a divider panel between two evaporators in an HVAC system, where air from fresh-air intake is directed over one active evaporator while preventing airflow over the deactivated evaporator, and the blower speed is adjusted to minimize condensate re-evaporation, using a supply duct, return duct, and multiple dampers to control airflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If air is circulated through the HVAC system during ventilation without operating the evaporator, then adequate ventilation is achieved, but condensed moisture evaporates and is re-introduced into the enclosed space
Solution Approach 1:
The evaporator assembly is segmented into multiple evaporators (first evaporator, second evaporator) with separate airflow paths controlled by independent damper assemblies. This allows selective operation where one evaporator can remain deactivated with its dampers closed to prevent condensate re-evaporation, while another evaporator handles the ventilation airflow, thus resolving the contradiction between maintaining ventilation capability and preventing harmful condensate re-evaporation.
Solution Approach 2:
Damper assemblies act as intermediaries between the airflow and evaporators. The dampers control and regulate airflow distribution to specific evaporators, enabling the system to direct ventilation air away from deactivated evaporators that have condensate accumulation, thereby preventing re-evaporation while maintaining overall ventilation function through the active evaporator.
2Productivity
If multiple evaporators are used to handle partial cooling loads, then system efficiency is improved, but airflow distribution and condensate management complexity increases
Solution Approach 1:
The system divides the cooling capacity into multiple evaporators that can operate independently or in combination based on load requirements. Each evaporator has its own damper assembly for independent airflow control, allowing the system to optimize cooling capacity by activating only the necessary number of evaporators, thus improving productivity while managing complexity through modular, independent control units.
Solution Approach 2:
The damper assemblies are designed to dynamically adjust airflow distribution to multiple evaporators based on operational conditions. During partial cooling loads, the system can dynamically deactivate certain evaporators and redirect their airflow paths through the dampers to active evaporators, enabling flexible adaptation to varying cooling demands while simplifying condensate management by keeping deactivated evaporators isolated from airflow.
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
Reduces condensate re-evaporation on inactive evaporators, lowering the relative humidity and energy demand by directing airflow effectively and minimizing re-evaporation during partial-cooling and ventilation modes.
Implementation Method 1
condensed moisture often accumulates on a surface of an evaporator. Such condensed moisture is representative of moisture that has been removed from air during operation of the HVAC system
Implementation Method 2
it is often necessary to circulate air through the HVAC system without operating an associated evaporator
Implementation Method 3
a divider panel directing air egressing the first plurality of dampers across the first evaporator and air egressing the second plurality of dampers across the second evaporator
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
An apparatus that includes a supply duct and a return duct fluidly coupled to the supply duct. A first evaporator is disposed between the supply duct and the return duct. A second evaporator is disposed between the supply duct and the return duct. A fresh-air intake is disposed between the supply duct and the return duct upstream of the first evaporator and the second evaporator. A first plurality of dampers are disposed upstream of the first evaporator. A second plurality of dampers are disposed upstream of the second evaporator. A divider panel is disposed between the first evaporator and the second evaporator. The divider panel directs air egressing the first plurality of dampers across the first evaporator and air egressing the second plurality of dampers across the second evaporator