Turbo chiller
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Solution Overview
Problem
The R1233zd(E) refrigerant, with its low global warming potential and ozone depletion potential, is unsuitable for use in chillers and air conditioners due to its low density and high sonic velocity, making it difficult to ensure suitable performance with scroll-type or rotary-type displacement compressors.
Innovation Solution
A turbo chiller configuration utilizing a turbo compressor with a direct drive configuration and magnetic or ceramic bearings, eliminating the need for a lubrication system and allowing the use of R1233zd(E) refrigerant, which reaches negative pressure at a saturation temperature of 18° C. or lower.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a turbo compressor with direct drive configuration and magnetic/ceramic bearings is used, then power loss and bearing losses are reduced enabling higher rotation for high flow rate refrigerant compression, but device complexity increases due to the specialized bearing system
Solution Approach 1:
The patent replaces traditional mechanical lubricated bearings with magnetic bearings or oil-free ceramic bearings in the turbo compressor. This substitution eliminates the need for lubricating oil and associated lubrication systems, reducing power loss and bearing losses while enabling higher rotation speeds suitable for high flow rate refrigerant compression with R1233zd(E)
Solution Approach 2:
The patent extracts and eliminates the lubrication system from the turbo compressor by using oil-free ceramic bearings or magnetic bearings. This removal of the lubrication system reduces device complexity in terms of maintenance requirements and eliminates power losses associated with oil circulation, while still enabling high rotation operation
2Object-affected harmful factors
If R1233zd(E) refrigerant is used, then global warming potential and ozone depletion potential are reduced, but refrigerant release during maintenance becomes an environmental concern
Solution Approach 1:
The patent extracts and eliminates the source of refrigerant release by adopting an oil-free configuration without a lubrication system. Since lubricating oil is not used, there is no need to drain oil from the compressor during maintenance, thereby preventing refrigerant that would be mixed with the oil from being released into the atmosphere
Solution Approach 2:
The magnetic bearing system operates without external lubrication, using magnetic fields to support the rotating shaft. This self-sustaining operation without lubricating oil eliminates the maintenance step that would otherwise cause refrigerant release, making the system inherently environmentally protective
3Power
If a speed-increasing gear unit is used to drive the impeller, then compression ratio is increased, but lubrication system complexity and maintenance requirements increase
Solution Approach 1:
The patent removes the speed-increasing gear unit and its associated lubrication system by adopting a direct drive configuration where the motor shaft is directly coupled to the impeller. This elimination maintains compression ratio through direct motor-impeller coupling while removing the complexity and maintenance requirements of gear lubrication
Solution Approach 2:
The patent merges the motor shaft directly with the impeller shaft, eliminating the intermediate gear unit. This merging of components achieves the desired compression ratio through direct coupling, thereby eliminating the need for a separate lubrication system for the gear unit and reducing overall device complexity
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 configuration reduces power loss and bearing losses, enabling higher rotation suitable for high flow rate refrigerant compression, while minimizing maintenance and environmental impact by reducing refrigerant release and utilizing the refrigerant's unique properties.
Implementation Method 1
the rotating shaft being supported by magnetic bearings
Implementation Method 2
turbo compressor with a specific configuration
Data Source
AI summary
A turbo chiller that has an oil-free configuration, which reduces the frequency of maintenance and maintenance-induced release of refrigerant, and can achieve a reduced environmental impact by utilizing the characteristics of the low-pressure refrigerant R1233zd(E) that reaches negative pressure at a saturation temperature of 18° C. or lower. The turbo chiller comprises a refrigeration cycle that includes a turbo compressor, a condenser, a decompression device, and an evaporator connected in sequence via piping and is filled with a refrigerant; wherein the refrigerant is a low-pressure refrigerant R1233zd(E) refrigerant with low global warming potential and low ozone depletion potential; the turbo compressor has a direct drive configuration in which a rotating shaft of impellers is directly joined to a motor; and the rotating shaft is supported by magnetic bearings.