Presents:

The Brumal Box

Group Members: Alex Landry, Andrew Dobbin, Russell Fulgencio and Kirk MacDonald

A part-by-part analysis...

I. FrameII. Refrigeration UnitIII. Inner ShellIV. Dispensing SystemV. InsulationVI. Outer Shell

The Brumal Box – Parts and Pieces

The frame of the prototype is constructed from 6” steel stud tracks and 1/16” aluminum angles. Total weight is 1.729 kg.

Frame - Prototype

Sold by LifeSpace, the design pictured below allows for optimal circulation within the refrigerator as well as minimal weight.

Frame – Production Model

Individual Wire length; .2286 m Cross-section area; .000008 m2

Total length required; 40 x .2286 m = 9.144 m Density of steel; 8000 kg/m3

Volume required; (9.144 m)x(.000008 m2) Volume of wire = .000073 m3

Mass of frame = (.000073 m3)x(8000 kg/m3) Mass = .584 kg

Approximate Mass of Production Frame

The peltier device in our prototype is set to run at 72 W.

Refrigeration Unit - Prototype

The size of the peltier device that will be used in our production model depends upon the cooling load.

Refrigeration Unit – Production Model

The inner shell is constructed of ½” pine wood.

Inner Shell - Prototype

A majority of modern fridges have interiors made of plastic. The plastic is a mix of ABS (Acrylonitrile butadiene styrene), polyurethane and polypropylene.

Inner Shell – Production Model

The dispensing system is computer operated, using a programmable Arduino board to run a single servo motor. A modified version of Arduino’s “Sweep” code is used to control the motion of the servo. This is a C++ code.

Dispensing System - Prototype

#include <Servo.h> Servo dispenser1; // define the servo int pos = 0; // variable to store the servo position void setup() { dispenser1.attach(9); // attach the servo to pin 9} void loop() { for(pos = 0; pos < 90; pos += 90) // goes from 0 degrees to 90 degrees { // in a 90 degree step dispenser1.write(pos); // tell servo to go to position in variable 'pos' delay(500); // 500 ms delay for the servo to reach the position } for(pos = 90; pos>=0; pos-=90) // goes from 90 degrees to 0 degrees { dispenser1.write(pos); // tell servo to go to position in variable 'pos' delay(500); // 500 ms delay for the servo to reach the position } }

A single motor can be used to scoop the available can out of the frame.

In keeping with theoriginal plan of construction a launcher, our finalmodel will requirea receiver.

Dispensing System – Production Model

W = IVW = (6A)(12V) = 72 W

B = QL/W0.8 = QL/72 QL = 57.6 W

W = QH - QLQH = 14.4W

Cooling Load

QH = A(T2 – T1)/Rtotal ; A =6.31ft2 (Surface Area)

14.4 = (6.31ft2)(77 – 73)/Rtotal

Rtotal = 9.20

Rtotal = Rwood1 + Rinsulator + Rwood2

Rinsulator = 9.20 – 2x(2.5) = 4.20

R Value Calculations

R value units: ft2*Fo/W

Fiberglass; R = 3.7(In use)

Polyurethane; R = 6.15(Ideal)

The prototype uses yellow fiberglass insulation, with an R value of roughly 3.14 – 4.10.

Insulation - Prototype

Polyurethane foam is the most widely used form of insulation in modern refrigerators. It is seen below being used as insulation in a house.

The R-value of polyurethanefoam is 6.15.

Insulation – Production Model

The outer shell is constructed of ¾ inch pine wood.

Outer Shell - Prototype

Outer Shell – Production Model

The use of wood for the inner and outer shell of the prototype adds considerable size to the Brumal Box.

The combined width of the inner and outer shell of the prototype is 1.25”, and is expected to be ¼” on the production model.

Size Comparison – Prototype VS Production