Sorption-Based HVAC/R System to Reduce Compressor Size and Energy Use
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Solution Overview
Problem
HVAC/R systems face challenges in reducing the size and energy usage of refrigerant compressors due to low suction pressure of refrigerant during regeneration, necessitating large and energy-intensive compressors.
Innovation Solution
The system incorporates a sorption circuit with a heat absorption heat exchanger and a sorption heat exchanger using sorbent materials like strontium chloride or barium chloride, along with a tertiary fluid compressor and heat exchange circuit that includes conditioning and ambient heat exchangers, allowing for thermal energy transfer and selective fluid flow direction to optimize compressor size and energy use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a refrigerant compressor is used to compress refrigerant at low suction pressure during regeneration, then the refrigerant can be compressed and circulated, but the compressor size and energy consumption increase significantly
Solution Approach 1:
A tertiary fluid is introduced as an intermediary medium between the low-pressure refrigerant and the compressor. The tertiary fluid absorbs thermal energy from the refrigerant in a heat exchanger, becomes compressed by a smaller compressor, and then releases its thermal energy to regenerate the refrigerant in the sorption heat exchanger. This intermediary approach allows using a smaller, more energy-efficient compressor while still achieving the required refrigerant regeneration.
Solution Approach 2:
The system changes the thermal energy transfer parameters by using a tertiary fluid with different thermal properties than the refrigerant. The tertiary fluid operates at different temperature and pressure levels, allowing the compressor to work at more favorable conditions with a smaller pressure ratio, thereby reducing compressor size and energy consumption.
2Reliability
If a large compressor is used to handle low suction pressure refrigerant, then adequate compression is achieved, but the system size and cost increase
Solution Approach 1:
The tertiary fluid serves as a mediator that decouples the refrigerant compression requirement from the actual compressor size. By transferring thermal energy through the tertiary fluid cycle, the system can use a smaller compressor that is appropriately sized for the tertiary fluid's pressure requirements rather than being oversized for the refrigerant's low suction pressure.
3Reliability
If thermal energy is used to regenerate refrigerant from adsorber material, then refrigerant is released for cooling cycles, but additional heat exchangers and fluid circuits are required
Solution Approach 1:
The tertiary fluid heat exchange circuit is designed to serve multiple functions: it provides thermal energy for refrigerant regeneration in the sorption heat exchanger, and can also be integrated with the heat absorption heat exchanger to provide cooling when needed. This multi-functionality reduces the need for separate dedicated systems for each function.
Solution Approach 2:
The system merges the regeneration heat exchanger and cooling heat exchanger functions into an integrated heat exchange circuit using the tertiary fluid. The control valves allow the tertiary fluid to be directed to different heat exchangers based on system needs, combining multiple functions into a single fluid circuit rather than requiring completely separate 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
This configuration reduces the necessary pressure ratio and size of the primary fluid compressor by an order of magnitude, enhancing energy efficiency and reducing system size, while also enabling the use of waste heat for regeneration, thereby improving overall system performance.
Implementation Method 1
a sorption heat exchanger including a volume of sorbent material to adsorb or absorb the primary fluid flow, generating thermal energy at the sorption heat exchanger
Implementation Method 2
The heat absorption heat exchanger is configured to exchange thermal energy between the primary fluid flow and a secondary fluid flow through the heat absorption heat exchanger
Implementation Method 3
The sorption heat exchanger is configured to transfer the generated thermal energy to a tertiary fluid flow through the sorption heat exchanger
Data Source
AI summary
A heating, ventilation, air conditioning and refrigeration (HVAC/R) system includes a sorption circuit including a heat absorption heat exchanger in fluid communication with a primary fluid flow source such that a primary fluid flow from is directed therethrough. The heat absorption heat exchanger is configured to exchange thermal energy between the primary fluid flow and a secondary fluid flow. A sorption heat exchanger includes a sorbent material to adsorb or absorb the primary fluid flow, generating thermal energy. The sorption heat exchanger is configured to transfer the generated thermal energy to a tertiary fluid flow. A heat exchange circuit is in fluid communication with the sorption circuit and includes a control valves connected to both the secondary fluid flow and the tertiary fluid flow configured to selectably direct the secondary fluid flow and/or the tertiary fluid flow to a conditioning heat exchanger or an ambient heat exchanger.