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Title: Development of a Water Based, Critical Flow, Non-Vapor Compression cooling Cycle

Abstract

Expansion of a high-pressure liquid refrigerant through the use of a thermostatic expansion valve or other device is commonplace in vapor-compression cycles to regulate the quality and flow rate of the refrigerant entering the evaporator. In vapor-compression systems, as the condensed refrigerant undergoes this expansion, its pressure and temperature drop, and part of the liquid evaporates. We (researchers at Kansas State University) are developing a cooling cycle that instead pumps a high-pressure refrigerant through a supersonic converging-diverging nozzle. As the liquid refrigerant passes through the nozzle, its velocity reaches supersonic (or critical-flow) conditions, substantially decreasing the refrigerant’s pressure. This sharp pressure change vaporizes some of the refrigerant and absorbs heat from the surrounding conditions during this phase change. Due to the design of the nozzle, a shockwave trips the supersonic two-phase refrigerant back to the starting conditions, condensing the remaining vapor. The critical-flow refrigeration cycle would provide space cooling, similar to a chiller, by running a secondary fluid such as water or glycol over one or more nozzles. Rather than utilizing a compressor to raise the pressure of the refrigerant, as in a vapor-cycle system, the critical-flow cycle utilizes a high-pressure pump to drive refrigerant liquid through the cooling cycle.more » Additionally, the design of the nozzle can be tailored for a given refrigerant, such that environmentally benign substances can act as the working fluid. This refrigeration cycle is still in early-stage development with prototype development several years away. The complex multi-phase flow at supersonic conditions presents numerous challenges to fully understanding and modeling the cycle. With the support of DOE and venture-capital investors, initial research was conducted at PAX Streamline, and later, at Caitin. We (researchers at Kansas State University) have continued development of the cycle and have gained an in-depth understanding of the governing fundamental knowledge, based on the laws of physics and thermodynamics and verified with our testing results. Through this research, we are identifying optimal working fluid and operating conditions to eventually demonstrate the core technology for space cooling or other applications.« less

Authors:
Publication Date:
Research Org.:
Kansas State University, 1700 Anderson Ave., Manhattan, Kansas 66506
Sponsoring Org.:
USDOE; USDOE Office of Energy Efficiency and Renewable Energy (EERE), Building Technologies Program (EE-2J)
OSTI Identifier:
1129868
Report Number(s):
DOE-KSU-0004173
DOE Contract Number:
EE0004173
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; non-vapor; compression cooling; water

Citation Formats

Hosni, Mohammad H. Development of a Water Based, Critical Flow, Non-Vapor Compression cooling Cycle. United States: N. p., 2014. Web. doi:10.2172/1129868.
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Hosni, Mohammad H. Development of a Water Based, Critical Flow, Non-Vapor Compression cooling Cycle. United States. doi:10.2172/1129868.
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Hosni, Mohammad H. Sun . "Development of a Water Based, Critical Flow, Non-Vapor Compression cooling Cycle". United States. doi:10.2172/1129868. https://www.osti.gov/servlets/purl/1129868.
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@article{osti_1129868,
title = {Development of a Water Based, Critical Flow, Non-Vapor Compression cooling Cycle},
author = {Hosni, Mohammad H.},
abstractNote = {Expansion of a high-pressure liquid refrigerant through the use of a thermostatic expansion valve or other device is commonplace in vapor-compression cycles to regulate the quality and flow rate of the refrigerant entering the evaporator. In vapor-compression systems, as the condensed refrigerant undergoes this expansion, its pressure and temperature drop, and part of the liquid evaporates. We (researchers at Kansas State University) are developing a cooling cycle that instead pumps a high-pressure refrigerant through a supersonic converging-diverging nozzle. As the liquid refrigerant passes through the nozzle, its velocity reaches supersonic (or critical-flow) conditions, substantially decreasing the refrigerant’s pressure. This sharp pressure change vaporizes some of the refrigerant and absorbs heat from the surrounding conditions during this phase change. Due to the design of the nozzle, a shockwave trips the supersonic two-phase refrigerant back to the starting conditions, condensing the remaining vapor. The critical-flow refrigeration cycle would provide space cooling, similar to a chiller, by running a secondary fluid such as water or glycol over one or more nozzles. Rather than utilizing a compressor to raise the pressure of the refrigerant, as in a vapor-cycle system, the critical-flow cycle utilizes a high-pressure pump to drive refrigerant liquid through the cooling cycle. Additionally, the design of the nozzle can be tailored for a given refrigerant, such that environmentally benign substances can act as the working fluid. This refrigeration cycle is still in early-stage development with prototype development several years away. The complex multi-phase flow at supersonic conditions presents numerous challenges to fully understanding and modeling the cycle. With the support of DOE and venture-capital investors, initial research was conducted at PAX Streamline, and later, at Caitin. We (researchers at Kansas State University) have continued development of the cycle and have gained an in-depth understanding of the governing fundamental knowledge, based on the laws of physics and thermodynamics and verified with our testing results. Through this research, we are identifying optimal working fluid and operating conditions to eventually demonstrate the core technology for space cooling or other applications.},
doi = {10.2172/1129868},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Mar 30 00:00:00 EDT 2014},
month = {Sun Mar 30 00:00:00 EDT 2014}
}
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Technical Report:
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DOI:  10.2172/1129868
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