CRAC Pre-Cooler Coil Layout for Higher Temperature Delta
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Solution Overview
Problem
Data centers face increased server temperature deltas and changing sensible and latent heat loads, leading to inefficient cooling and excessive air flow, as existing CRAC systems struggle to manage the temperature difference across cooling coils effectively.
Innovation Solution
A computer room air conditioner (CRAC) with a configuration of multiple cooling coils arranged in series, where an upstream cooling coil provides pre-cooling and the downstream coil handles additional sensible and latent cooling needs, with a controller optimizing the cooling output to enhance temperature delta and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a single cooling coil is used in the CRAC system, then the device complexity is reduced, but the temperature delta across the cooling coil is insufficient and cooling efficiency decreases
Solution Approach 1:
The cooling coil is segmented into multiple sections (first cooling coil section and second cooling coil section) arranged in series within the airflow path. This segmentation allows each section to contribute to the overall temperature reduction, thereby increasing the total temperature delta across the CRAC system while maintaining a manageable structural complexity through modular design.
Solution Approach 2:
The patent extends the cooling process into an additional dimensional aspect by introducing multiple cooling coil sections along the airflow path rather than relying on a single coil. This dimensional extension of the cooling trajectory enables greater temperature differential without proportionally increasing device complexity, as the sections are integrated into the existing airflow structure.
2Productivity
If the CRAC system is designed to handle both sensible and latent heat loads with a single cooling coil, then the device complexity is minimized, but the cooling efficiency and energy utilization are suboptimal
Solution Approach 1:
The cooling system is segmented into multiple cooling coil sections that can be independently controlled through separate control circuits. This segmentation enables differential control strategies where each section can be optimized for specific cooling requirements (sensible or latent heat removal), thereby improving overall cooling efficiency and energy utilization while managing device complexity through modular control architecture.
Solution Approach 2:
The patent implements dynamic control of the cooling system by introducing separate control circuits for each cooling coil section. These control circuits can dynamically adjust the operation of individual sections based on real-time cooling demands, enabling the system to adaptively optimize cooling efficiency for varying sensible and latent heat loads without requiring a fundamentally more complex static configuration.
3Loss of energy
If excessive air flow is used to meet cooling demands, then the cooling capacity is sufficient, but energy waste increases and system efficiency decreases
Solution Approach 1:
The first cooling coil section performs preliminary cooling action on the air stream before it reaches the second cooling coil section. This staged preliminary cooling approach allows the system to progressively reduce air temperature and humidity, thereby achieving the required cooling capacity with optimized air flow rates and reduced energy waste compared to single-stage cooling systems that require excessive air flow to meet the same cooling demands.
Solution Approach 2:
The cooling process is segmented into multiple stages with separate cooling coil sections, each contributing to the overall cooling capacity. This segmentation enables the system to achieve sufficient cooling capacity through efficient multi-stage heat removal rather than relying on high-volume single-stage cooling, thereby reducing energy waste while maintaining adequate cooling performance.
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 increases the maximum temperature delta across the CRAC, improving cooling capacity and enabling efficient latent cooling, reducing energy waste and enhancing cooling efficiency by optimizing the use of upstream and downstream cooling circuits based on heat load and environmental conditions.
Implementation Method 1
an upstream cooling coil and a downstream cooling coil. The cooling coils are arranged so that air drawn into the CRAC passes through the cooling coils in serial fashion
Implementation Method 2
The downstream cooling coil is controlled to provide any additional sensible cooling that may be needed as well as any latent (dehumidification) that may be needed
Data Source
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AI summary
A computer room air conditioner ("CRAC") has a cabinet having an air inlet through which return air from an area is drawn and an air outlet through which air cooled by the CRAC is exhausted. An air moving unit is disposed in the cabinet as are a plurality of cooling coils, which are in separate cooling circuits. The cooling coils are arranged so that the air passes through the cooling coils in serial fashion, that is, first through an upstream cooling coil and then through a downstream cooling cool. The upstream cooling coil acts as a pre-cooler to the subsequent downstream cooling coil. The CRAC includes a controller that controls the cooling provided by the cooling circuits. The controller controls the cooling provided by the upstream cooling circuit so that when it is being used to provide cooling, it provides only sensible cooling.