JUMP GE Call for Innovation

LOW-TEMPERATURE INTRINSICALLY SAFE DEFROST SYSTEM

Background

Nearly 100% of US household refrigerators use R-134a as a refrigerant. However, in many other countries throughout the world, R-600a (isobutane) is used. The benefits of R-600a include: 1) significantly lower global warming potential (GWP), 2) typically lower sound level, and 3) lower energy usage (approximately 4%). The technical specifications and service procedures required to use R-600a as a refrigerant in the US have been developed. Nevertheless, the current barrier-to-entry for manufacturers to use R-600a is the cost of complying with UL 250 (Standard for Safety for Household Refrigerators and Freezers) to ensure customer safety. Specifically, because R-600a is an A3 refrigerant (i.e., low toxicity and high flammability) all electrical devices need to be spark resistant and no surface temperature should exceed 680°F.  

During operation of a refrigerator, moisture from the air condenses and freezes on the evaporator. For the forced convection (frost-free) products that make up the entire population of US primary household refrigerators, a defrost heater is used to remove this frost from the evaporator coil. The heater is cycled at regular intervals to maintain cooling performance. In a typical configuration, a defrost heater is placed between the evaporator and a drain pan. The defrost heater warms the evaporator and melts the frost until a pre-determined temperature is reached. The melt water is removed from the refrigerator via a drain line connected to the drain pan. While effective, surface temperatures of the defrost heater may reach 1000 to 1400°F.                 

The Challenge

The challenge is to develop a low-cost system to remove ice from the evaporator while conforming to UL 250 Flammable Refrigerants Addendum. Specifically, the defrost system

• Must not require substantial physical changes to the existing evaporator or evaporator compartment
• Must meet standard 20-year life requirements (assume 1 defrost per day)
• Must be able to raise an unfrosted evaporator from -10°F to 40°F in 15 minutes or less
• Must be spark resistant and surface temperatures should not exceed 680°F.
• Should be able to raise an unfrosted evaporator from -10F to 40F in 15 minutes or less.  

The Award

A cash award of $3,000 will be sponsored by GE for the top selected technology submission. The idea submitter will also be invited to discuss future collaboration with GE and ORNL technical experts. Depending on the needs identified:

• ORNL may provide in-kind technical support of $10,000 - $20,000 to enable ORNL staff to provide prototype development, testing, 3rd party validation, or other defined needs.
• Participation in the DOE Small Business Voucher (SBV) pilot will also be discussed; ORNL may provide in-kind technical support of up to $300K through the SBV program, if SBV approved.

Idea Submission Deadline

Idea Submission Period Ends: Friday, April 8, 2016 at 11:59 PM EST

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