Featured Research

from universities, journals, and other organizations

Using Liquid To Cool Grocery Cases Saves Energy, Better For Environment

Date:
April 9, 1998
Source:
University Of Illinois At Urbana-Champaign
Summary:
Refrigerants leaking from systems that chill supermarket display cases are a leading source of environmental pollution. Recent tests by a team of University of Illinois researchers indicate that an alternate method of refrigeration can reduce leakage and save money.

CHAMPAIGN, Ill. -- Refrigerants leaking from systems that chill supermarket display cases are a leading source of environmental pollution. Recent tests by a team of University of Illinois researchers indicate that an alternate method of refrigeration can reduce leakage and save money.

"There are approximately 30,000 large supermarkets in the United States, and the typical supermarket leaks about 1,500 pounds of refrigerants annually," said Predrag Hrnjak, a professor of mechanical and industrial engineering and a researcher at the university's air conditioning and refrigeration center. "This is a huge problem. In fact, supermarkets are second only to automotive air-conditioning systems in polluting the atmosphere with refrigerants."

One potential solution is to replace the high-pressure gas used in conventional refrigeration systems with a low-pressure liquid, Hrnjak said. "Circulating a liquid refrigerant a technique called secondary cooling can increase energy efficiency, reduce refrigerant leakage, and utilize a centralized refrigeration unit that is more reliable and less expensive to operate."

While thousands of European supermarkets have switched to the secondary cooling technology, the idea has been slow to catch on in other parts of the world. In the United States, for example, about 100 supermarkets have been converted.

One reason for the slow acceptance, Hrnjak said, is that "few tests have been performed to determine which system is actually more efficient. Nor do we know which fluid is the best one to use."

To answer such questions, Hrnjak, research engineer Yanhui Mao and graduate research assistant Wilson Terrell Jr., compared the performance of a typical supermarket display case operating with a conventional refrigerant (R404A) and with two different secondary coolants (potassium formate and potassium acetate). The researchers placed a display case, filled with simulated food packages, in an environmental chamber and monitored package temperatures as a function of refrigerant temperature.

"We found that the display case performed better with potassium formate as a secondary coolant than with the conventional refrigerant," Hrnjak said. "Our tests showed that the same product temperature could be achieved with a higher operating temperature of secondary coolant.

"For example, to maintain frozen foods at the proper temperature, the R404A refrigerant must have an inlet temperature of -32.5 degrees Centigrade," Hrnjak said. "The same product temperature, however, could be achieved with potassium formate at an inlet temperature of only -26.5 degrees Centigrade. This is a significant difference in temperature and the amount of refrigeration required."

The preliminary results "indicate that secondary cooling is a cost-effective and energy-efficient alternative to conventional refrigeration. And it's better for the environment," Hrnjak said.

The researchers presented their findings at the International Institute for Refrigeration conference, held in Cambridge, England, March 29-April 1.


Story Source:

The above story is based on materials provided by University Of Illinois At Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University Of Illinois At Urbana-Champaign. "Using Liquid To Cool Grocery Cases Saves Energy, Better For Environment." ScienceDaily. ScienceDaily, 9 April 1998. <www.sciencedaily.com/releases/1998/04/980409080701.htm>.
University Of Illinois At Urbana-Champaign. (1998, April 9). Using Liquid To Cool Grocery Cases Saves Energy, Better For Environment. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/1998/04/980409080701.htm
University Of Illinois At Urbana-Champaign. "Using Liquid To Cool Grocery Cases Saves Energy, Better For Environment." ScienceDaily. www.sciencedaily.com/releases/1998/04/980409080701.htm (accessed July 22, 2014).

Share This




More Matter & Energy News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Government Approves East Coast Oil Exploration

Government Approves East Coast Oil Exploration

AP (July 18, 2014) The Obama administration approved the use of sonic cannons to discover deposits under the ocean floor by shooting sound waves 100 times louder than a jet engine through waters shared by endangered whales and turtles. (July 18) Video provided by AP
Powered by NewsLook.com
Sunken German U-Boat Clearly Visible For First Time

Sunken German U-Boat Clearly Visible For First Time

Newsy (July 18, 2014) The wreckage of the German submarine U-166 has become clearly visible for the first time since it was discovered in 2001. Video provided by Newsy
Powered by NewsLook.com
Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Reuters - US Online Video (July 17, 2014) President Barak Obama stopped by at a lunch counter in Delaware before making remarks about boosting the nation's infrastructure. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

TheStreet (July 16, 2014) Oil Futures are bouncing back after tumbling below $100 a barrel for the first time since May yesterday. Jeff Grossman is the president of BRG Brokerage and trades at the NYMEX. Grossman tells TheStreet the Middle East is always a concern for oil traders. Oil prices were pushed down in recent weeks on Libya increasing its production. Supply disruptions in Iraq fading also contributed to prices falling. News from China's economic front showing a growth for the second quarter also calmed fears on its slowdown. Jeff Grossman talks to TheStreet's Susannah Lee on this and more on the Energy Department's Energy Information Administration (EIA) report. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins