Advanced Heat Exchanger Coatings to Improve Energy Efficiency of Industrial Refrigeration System

Industrial and Agricultural Innovation Industrial Refrigeration and Cooling

Nelumbo Inc.

Recipient

Hayward, CA

Recipient Location

10th

Senate District

20th

Assembly District

beenhere

$1,750,114

Amount Spent

closed

Completed

Project Status

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Project Result

The project team is finalizing the final report for submission to the CEC by mid-March, after delays in third-party measurement and verification (M&V) took longer than expected.

The Issue

Industrial refrigeration systems rely on refrigerant-to-air heat exchangers to create temperature-controlled space. Ice continually forms on evaporator coils because their surface is below the freezing point of water and moisture from the air will condense, freeze, and form frost. Frost formation diminishes the ability of the coil to cool the air by acting as a thermal barrier and blocking the flow of air. Overtime frost diminishes system efficiency and leads to inadequate cooling and system failure which necessitates the need to defrost. Defrost is an energy intensive process which accounts for up to 21% of the energy consumption of refrigerated systems through direct consumption of energy.

Project Innovation

Nelumbo, Inc. has developed surface modified coated evaporator coils to address the inefficiencies from frost formation and the need to defrost. To date there are no anti-ice coating products available for industrial heat exchangers. The surface modification will use an innovative advanced coating comprised of a nano-structured ceramic to overcome these barriers by (1) reducing the onset of frost formation, (2) slowing the rate of frost growth, and (3) enhancing the removal of frost. The project's goal is to advance the Technology Readiness Level (TRL) of the innovative advanced coating technology from TRL 3 through TRL 5. During this process, the technology will be taken from proof of concept component to an extensively tested at the system level in a laboratory environment to develop the dataset necessary to verify performance prior to future field deployment projects.

Project Goals

Project goals are to reduce industrial refrigeration equipment energy consumption by 15%.

Project Benefits

To date there are no anti-ice heat exchanger technologies available for industrial refrigeration heat exchangers. Previous research into anti-ice coating technologies have relied on polymers and fluorinated-compounds which are brittle at low temperatures, are not durable under the thermal cycling, and/or not chemically stable to the cleaning requirements in the industrial refrigeration sector. The competitive advantage of Nelumbo's advanced coating over other attempted anti-ice coatings is that it is a durable ceramic that is chemically bonded to the surface. The ceramic utilizes both surface chemistry and nanostructuring to reduce the rate of ice formation and repel water. It is thin, conformal, durable, and strongly bonded to the surface which allows the coating to flex during the expansion and contraction which occurs during freeze and defrost cycles.