Free cooling operation of a chiller
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional chiller systems with free cooling techniques have extraneous components that increase part count and cost, are limited in refrigerant options, and suffer from pressure losses that reduce cooling capacity.
Innovation Solution
A chiller system with a passive compressor that levitates the rotor using magnetic or rolling element bearings, allowing refrigerant to flow through without powering the motor, and employs variable geometry diffusers and pre-rotation vanes to maintain cooling capacity during free cooling mode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If traditional free cooling techniques are used with compressor bypass valves, then the system can operate without powering the compressor during low ambient temperatures, but the system includes extraneous components that increase part count and cost
Solution Approach 1:
The patent removes the compressor bypass valve component from the system by redesigning the compressor internal geometry. The compressor housing and internal passages are shaped to naturally guide refrigerant flow through the compressor during free cooling mode without requiring external bypass valves, thereby reducing part count while maintaining the ability to operate without compressor power during low ambient temperatures
Solution Approach 2:
The compressor is designed to perform multiple functions: during normal operation it compresses refrigerant, and during free cooling mode it serves as a passive flow passage. The internal geometry of the compressor is configured to accommodate both compressed refrigerant flow and passive refrigerant flow through the same component, eliminating the need for separate bypass routing and reducing overall system complexity
2Use of energy by stationary object
If traditional free cooling techniques are used with compressor bypass valves, then the system can operate without powering the compressor, but the system is limited in the types of refrigerants that can be used
Solution Approach 1:
The patent modifies the internal geometric parameters of the compressor, including passage shapes, angles, and dimensions, to optimize flow characteristics for different refrigerant types. This geometric optimization allows the compressor to handle various refrigerants with different viscosity and density characteristics during passive flow mode, expanding refrigerant compatibility while maintaining the free cooling capability
3Use of energy by stationary object
If traditional free cooling techniques are used with compressor bypass valves, then the system can operate without powering the compressor, but pressure losses reduce cooling capacity
Solution Approach 1:
The patent incorporates variable geometry diffusers and pre-rotation vanes within the compressor that can be adjusted based on operating mode. During free cooling mode, these components are positioned to optimize passive refrigerant flow and minimize pressure losses, while during normal compression mode they serve their traditional functions. This dynamic adjustment maintains cooling capacity during free cooling operation by reducing pressure losses compared to fixed-geometry bypass systems
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 part count, complexity, and cost while maintaining cooling capacity, and enables use of a wide range of refrigerants without substantial pressure losses.
Implementation Method 1
A chiller system with a passive compressor that levitates the rotor using magnetic or rolling element bearings
Implementation Method 2
A chiller system with a passive compressor that levitates the rotor using magnetic or rolling element bearings
Implementation Method 3
employs variable geometry diffusers and pre-rotation vanes to maintain cooling capacity during free cooling mode
Implementation Method 4
employs variable geometry diffusers and pre-rotation vanes to maintain cooling capacity during free cooling mode
Implementation Method 5
The cooling fluid may be cooled in the cooling tower (or other water or cooling fluid source) via ambient air
Implementation Method 6
The cooling fluid may be cooled in the cooling tower (or other water or cooling fluid source) via ambient air
Data Source
AI summary
A heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system (10) includes a vapor compression system (14) having an evaporator (38), a condenser (34), and a compressor (32). The compressor (34) is configured to guide a refrigerant therethrough in a normal operating mode of the vapor compression system (14) and in a free cooling mode of the vapor compression system (14). The HVAC&R system (10) also includes a controller (40) configured to enable supply of power to a motor (50) of the compressor (34) in the normal operating mode and to suspend supply of power to the motor (50) of the compressor (34) in the free cooling mode.