Year: 2014

Project: Zero-Energy Thermal Refrigerator Frame

Client: Anthony International

Category: Engineering

My Role: Design engineer a refrigeration frame that uses zero energy, typically provided by a heated wire system, to heat the display and shield from cold temperature elements that create condensation on glass. By doing so a new frame will reduce energy cost, energy consumption, and materials. The solution proposed was to start by redesigning the current Anthony 101X-LE frame and add thermal insulation.

Objective

When customers open and close the freezer door at the supermarket, the glass on the inside will fog making it difficult to see all of the products inside. The task is to create a more sustainable energy method to eliminate the fog without using the standard energy-sapping door heaters. The approach is to design and test whether thermal insulation materials can be used instead. 

3D Concepts

FRAME CROSS SECTIONS: Multiple frame concepts were developed highlighting where thermal insulators would provide optimal efficiency.

COMPUTER SIMULATION EXPERIMENT:

Thermal Analysis of Perimeter and Mullion

As expected, when the insulation performance increases, the temperatures on the surface got warmer. The vacuum insulated panel (VIP) performed the best, but the initial designs do not fully pass the condensation criteria and goal to keep the surface temperature above 58˚F. The experiment parameters had three thermal insulators programmed accordingly in the conditions below:

Case Temperature

-15˚F

Relative Humidity

55%

Room Temperature

75˚F

PHYSICAL EXPERIMENT:

Thermal Analysis Objective

In order to reduce energy consumption, adding insulation reduces the heat transfer rate in order to maintain the same surface temperature with less energy input. This quick lab test will evaluate if VIP is able to reduce heat transfer rate. Determine the reduction in heat transfer due to the effect of vacuum insulation sections then compare to existing measured frame surface temperatures in freezing conditions.

Lab Equipment

Lab Experiment Set-up

Lab Experiment Results

The final results showed a considerable reduction in the required watt density to maintain surface temperatures using VIP, and were as followed: 

Perimeter Frame Section

49% reduction

(3.2 w/ft)

Mullion Section

31% reduction

(1.6 w/ft)

FINAL DESIGN:

Zero Energy Frame Concept

Taking into account the simulation and laboratory thermal analysis, new designs were created to further approach our goal of a zero-energy frame. Redesigns also include full CAD parts to provide realistic results in the next stage of thermal analysis, complete BOM layout, and continue focus implementing vacuum insulated panels.  

Perimeter Cross Section

Mullion Cross Section

© 2020 Design By Jonny Tran. www.Jonnyntran.com