Water Chiller With Switchable Air Flow for Free and Mechanical Cooling
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Solution Overview
Problem
Existing water chillers require two separate systems for free cooling and mechanical cooling, leading to high energy consumption and increased costs due to the series configuration of condensers and free cooling heat exchangers, which doubles the pressure drop and reduces efficiency.
Innovation Solution
A water chiller with a refrigeration apparatus and a free cooling heat exchanger, featuring controllable air flow direction means, such as louvers, that can selectively direct air flow between the free cooling heat exchanger and condenser, allowing for operation in either free cooling or mechanical cooling configurations based on ambient temperature, thereby optimizing energy use and reducing the need for dual systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the condensers of the refrigeration apparatus are placed in series with the free cooling heat exchangers to enable selective operation of both modes within a single system, then the system can perform both free cooling and mechanical cooling, but the air flow has to circulate successively through two exchangers which doubles the pressure drop and induces high power consumption on the fans
Solution Approach 1:
The patent applies the dynamics principle by making the air flow path configurable through movable louvers that can redirect air flow between different configurations. The system dynamically switches between series configuration (for free cooling mode) and parallel configuration (for mechanical cooling mode), allowing optimal performance in each mode without being constrained by a fixed series arrangement. This dynamic reconfiguration resolves the contradiction by enabling versatility while avoiding the continuous energy penalty of series flow.
Solution Approach 2:
The patent segments the air flow path into separate controllable channels using louvers that can independently direct air flow. By segmenting the flow paths, the system can choose to route air through only the necessary heat exchanger in each mode, rather than forcing air through both exchangers in series. This segmentation allows the system to achieve both operational modes while minimizing pressure drop and fan power consumption in each specific mode.
2Reliability
If two different water chillers are used for free cooling and mechanical cooling respectively, then each system can be optimized for its specific function, but the building incurs high cost and high volume with large footprint
Solution Approach 1:
The patent merges the free cooling and mechanical cooling systems into a single integrated water chiller unit. By combining both cooling capabilities in one system with shared components (compressor, condensers, expansion valve, evaporator, and fans), the patent reduces the overall footprint and eliminates the need for two separate chiller units. The merging is made possible through the controllable air flow direction means that allow the single system to adapt its configuration based on operational mode.
Solution Approach 2:
The patent implements universality by designing a single water chiller system that can perform both free cooling and mechanical cooling functions. The system uses controllable air flow direction means (louvers) to universally handle different operational requirements, making one system capable of replacing two specialized systems. This multi-functionality maintains optimized performance for each mode while significantly reducing the total equipment footprint and installation space.
3Adaptability or versatility
If free cooling heat exchangers are installed in series with condensers to enable selective operation, then both modes can be performed within a same system, but the pressure drop is doubled which reduces overall system efficiency
Solution Approach 1:
The patent applies dynamics by implementing a controllable air flow direction system with movable louvers that can dynamically reconfigure the air flow path based on operational mode. In free cooling mode, the louvers direct air through both the condenser and free cooling heat exchanger in series. In mechanical cooling mode, the louvers redirect air to flow through the condenser and evaporator in parallel, avoiding the series configuration penalty. This dynamic reconfiguration maintains versatility while minimizing energy losses in each specific operating condition.
Solution Approach 2:
The patent changes the operational parameters of the heat exchanger arrangement by using controllable air flow direction means to alter the flow path configuration. The system transitions between series and parallel arrangements based on the cooling mode required, effectively changing the system parameters (flow path topology) to optimize efficiency for each mode rather than being locked into a fixed series configuration that always incurs doubled pressure drop.
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
Enables efficient operation in varying temperature conditions with reduced energy costs and improved performance by selectively engaging free cooling or mechanical cooling modes without the inefficiencies of dual systems, maintaining low energy consumption and preserving the chiller's footprint.
Implementation Method 1
the refrigeration apparatus comprising a refrigerant circuit functioning in closed loop, the refrigerant circuit comprising a compressor, at least one condenser, an expansion valve and an evaporator, said condenser being configured to release heat from the refrigerant to the air flow under action of said at least one fan
Implementation Method 2
said evaporator being configured to draw heat from the water flow to cool down said water flow
Implementation Method 3
at least one free cooling heat exchanger, configured to be exposed to the air flow, and connectible to the water circuit
Data Source
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AI summary
This water chiller (2) comprises at least one refrigeration apparatus (8), a water circuit (10) in which circulates a water flow (100) to be cooled down, and at least one fan (12) generating an air flow (F1) that is aspired from the outside. The refrigeration apparatus (8) comprises a refrigerant circuit (80) functioning in closed loop and comprising a compressor (82), at least one condenser (84), an expansion valve (86) and an evaporator (88). The condenser (84) is configured to release heat from the refrigerant to the air flow (F1) under action of said at least one fan (12), the evaporator (88) is configured to draw heat from the water flow (100) to cool down said water flow (100). The water chiller (2) further comprises at least one free cooling heat exchanger (14), configured to be exposed to the air flow (F1), and connectible to the water circuit (10). The water chiller (2) comprises controllable air flow direction means (16) adapted to selectively direct the air flow (F1) towards the away from said at least one free cooling heat exchanger (14), in a mechanical cooling configuration in which the refrigeration apparatus (8) is running and said at least one free cooling heat exchanger (14) is disconnected from the water circuit (10), or direct the air flow (F1) through said at least one free cooling heat exchanger (14), in a free cooling configuration in which the refrigeration apparatus (8) is stopped and said at least one free cooling heat exchanger (14) is connected to the water circuit (10).