Abstract--
The importance of refrigeration i s fundamental in meeting the United Nations Millennium development goals, particularly for t h e millions of the world’s poor living in the t r o p i c s . dissigno set out determine the physically v i a b i l i t y to produce sufficient refrigeration to make ice from a Ranque-Hilsch Vortex tube. The base o b j e c t i v e s were, 1 kg of ice produced per work cycle, cost l e s s than $500 installed, minimal moving parts, only use renewable energy, & limit impact to t h e environment. The model began with a computational understanding of the real-world performance of t h e Ranque Hilsch vortex device. The results s u g g e s t s that all of the objectives can be met with the added benefits of water creation, heat, increased combustion efficiency, & energy storage. The
interpretation of the performance has provided t h e basis for dissigno’s project to create, sell, & maintain ice manufacturing as a sustainable
b u s i n e s s .
I. INTRODUCTION
The phenomenon of two gas streams separated without mechanical assistance was discovered by George J. Ranque in 1933 and the subject of a US Patent in 1934. The tube later became known as the Ranque-Hilsch Vortex tube. Compressed gas, air, enters the device tangentially to create
a vortex that travels through a generation chamber. The air is then reflected with a conical valve. The conical valve adjusts the balance of the amount of air that is allowed to escape and the amount that is forced back through the axis of the vortex. This balance is known as the cold fraction. The temperature drop is a function of the ambient temperature, pressure, cold fraction, and flow of compressed gas. Cold exit temperatures
can reach as low as -40ºC. The explanation of this phenomenon has been the center of much research since its discovery. There is still no universally
adopted theory that explains the effect of the vortex. The vortex tube is considered to be the result of several simultaneous phenomenon Ahlborn & Groves[6]. This work will not attempt to further explain or improve the vortex device.
There are limited practical applications due to the inherit inefficiency. The coefficient of performance (COP) was calculated as 0.08 [2]. In addition, the lack of available pressurized air is obstacle for a rural application. There are commercially available devices for industrial applications such as machining spot cooling, workers cold jackets, and electrical cabinet cooling in electrically classified areas. These devices require industrial sized oil free air compressors with low (-40 ºC) dew point to achieve optimal performance. Improvement of the vortex device generally results in complication of construction or power [3]. This increase in complexity hinders the physically viability in developing communities. The purpose of our work was to determine the physical viability of using the Ranque-Hilsch vortex tube as means for rural refrigeration. The device must be able to independently produce 1 kg of ice per work cycle, cost less than $500
installed, minimize moving parts, use renewable energy, and minimize impact to the environment. The vortex tube’s design, despite its inefficiency, has the advantage of simplicity, no chemicals, minimal maintenance, low cost, & very low exit temperatures. Our work suggests
that the vortex tube refrigerator is physically viable. Further work must be done to more efficiently produce compressed air in a rural setting. Actual application of the refrigerator is dependent on the economic, cultural, & climatic viability in the community of its installation.
II. EXPERIMENT
The experiment is an optimization problem so the system was
broken into the basic energy components. Each part of the
system is going to be studied to determine the impact of cold
fraction, flow, and pressure and on refrigeration performance.
The estimated refrigeration will then be compared to the
amount of energy to create ice. Then we will look into sizing
a compressor to meet those energy needs. We will examine
some untraditional means of compressing air. Basic ambient
conditions were established as constant. Ambient air and water
temperature, Ta was 21ºC. The elevation was set at 0 meters
above sea level.
A. Ice Production The first step in determining viability is developing a system that will be able to store the refrigeration energy. We have chosen water due to wide availability, environmental sensitivity, and attainable latent heat of fusion [3]. A base standard for production to be VT=1.00 x 10-3 m3. The density of water defined to remain constant at _W=1000 kg/m3. Equation 1 then gives the mass of water (mW) as 1.00 kg of water.

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