SUSTAINABLE SMALL CHILLERS FOR AGRICULTURAL AND RURAL APPLICATIONS

Recipient Organization
ENERGY CONCEPTS COMPANY, LLC
627 RIDGELY AVE
ANNAPOLIS,MD 214011062

Performing Department
Energy Concepts Co.

Non Technical Summary
This project will develop an innovative refrigeration cycle to allow small scale refrigeration with low emissions and high energy efficiency. The innovations expand on the propane fired Diffusion Absorption Chillers (DAC) already used in millions of RVs, allowing these cycles to be powered by heat from renewable energy sources such as solar thermal, geothermal, waste heat, biogas, or biomass. This chiller has no moving parts and uses refrigerants with no global warming and zero ozone depleting potential. The innovations involve modifying the generator to take in more heat and improve efficiency; and optimizing the bubble pump, to allow operation over a wider temperature range and higher capacity. The innovations are primarily in the generator / rectifier portion of the cycle, hence the name "Diffusion Absorption Cycle with Generator Recitifier", or DACGR. This will enable walk-in size or larger coolers, and allow sub-freezing temperatures. Air conditioning, heat pumping, medical storage, and drying, are also possible with DACGR, providing low energy storage and cooling options for millions of rural and urban users. The proposed DACGR systems would specifically benefit agricultural communities, especially those with less reliable grid electricity and/or high utility rates.The proposed DACGR innovations will be modeled, designed, fabricated, and tested in Phase I. Potential applications for community cold storage in Alaska, utilizing power plant waste heat or renewable energy, will be developed.Energy Concepts is a world leader in absorption cycles, and will apply know-how developed in industrial applications to the smaller scale diffusion absorption refrigerator. University of Alaska, including the Alaska Center for Energy and Power, has keen interest in promoting energy efficiency, renewable energy, sustainability, and resilience in rural Alaskan communities. It has direct knowledge of existing energy systems that can be integrated to provide energy neutral chilling. Energy Concepts industrial partners- Gaia Energy Research Institute, Cambridge Capital, and Sunrise CSP- can provide commercialization assistance with subsequent future awards, turning this innovation into a commercial product.

Animal Health Component

Research Effort Categories

Basic

Applied

Developmental

100%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
503	5310	2020	25%
401	5310	2020	25%
402	5310	2020	25%
132	5310	2020	25%

Knowledge Area
401 - Structures, Facilities, and General Purpose Farm Supplies; 132 - Weather and Climate; 503 - Quality Maintenance in Storing and Marketing Food Products; 402 - Engineering Systems and Equipment;

Subject Of Investigation
5310 - Machinery and equipment;

Field Of Science
2020 - Engineering;

Keywords

Goals / Objectives
The Phase I technical objectives are todesign and test the combination of bubble pump and thermosyphon generators with heat integrated rectification. Tests will help answer the question- Can the combination of bubble pump and thermosyphon generators help increase DAC operating range (capacity and/or temperature) and improve efficiency by reducing rectification losses.Non-technical objectives are to conductMarket Analysis and generate a Commercialization Plan. This task will help answer the question- How to successfully develop the technology through Phase II and Phase III (field demonstration), and what are the needs of the initial target markets and user.

Project Methods
A test stand will be fabricated using fabrication techniques such as welding, threading, flange fit up, and electric wiring, using ammonia refrigeration safety codes, standards and best practices. Tests will be run capturing temperature, pressure, flow, level data, which will be used in software to calculate energy and mass flows and balances. Existing databases, contact networks, and literature searches will be used to characterize market size and features to make the eventual commercialized product a success for the intended market.Results of the testing and modeling performed in Phase 1 will inform an application for Phase 2 funding, where a commercial product wil be designed and tested. The market applications will be studied by University of Alaska Fairbanks partners. The Alska Center for Energy and Power will bring their knowledge and experience of previous energy systems to evaluate the viability of this technology. They will also consult various stakeholders, such as villages, tribes, and co-ops, to evaluate the market potential of renewable heat powered refrigeration.

Progress 07/01/22 to 02/28/23

Outputs
Target Audience:The target audience for hearing the technical outcomes of this project are federal and state fuding agencies such as USDA NIFA, and Alaska Center for Energy and Power. The target audience for hearing technical innovations, product development, and market applications is existing refrigerator manufacturers; rural development agencies that know of underserved communities that need lower cost food storage options; and refrigeration distributrors and contractors that know of customer needs that are going unmet. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?The results of the technical development and market analysis were used to write a Phase 2 proposal. Potential market development partners will be contacted on an individual basis. Since this is not yet a fully developed product, the communities surveyed were not approached yet to host a demonstration site. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Several different geometries of bubble pumps were fabricated and tested. Three different thermosyphon generators, with different flow paths, were fabricated and tested. Heat integrated rectification was done on the test stand in several different configurations relative tot he generators. Data was usedto confirm the model predicting thermodynamic performance of vapor generation and other key performance indicators. The fabricated test stand, data measurement and analysis, and model development, moved this innovation from TRL 2 to TRL 4. A survey was conducted among organizations servng villages, tribes and rural communities of Alaska and other northern climes. Market analysis was performed to determine size of market for sustainable communnity size chillers, the gaps this innovation could fill, and potential partners to help bring the innovative product to market.

Publications