Share

Optimized on-off controller for energy saving in a household refrigerator.

Number: pap. 2401

Author(s) : SAFFAR U. C. E., MAIA A. A. T.

Summary

The domestic refrigerator is responsible for 30% of the average household electricity consumption in Brazil, and the power costs regarding a single refrigerator represents up to 5% of the Brazilian minimum wage. The capacity control method employed in most of these systems consists of a thermostat used to turn the compressor on and off to maintain the temperature between the desired levels. This method of capacity control is responsible for efficiency losses as a result of the start-up and shut-down transients. The duration and the number of on/off cycles directly influence the temperature profile inside the refrigerator and the system energetic efficiency. By adjusting the thermostat, the maximum and minimum temperature achieved during the system operation are changed, as well as the range between them. Having all that in mind, the aim of this study is to optimize the temperature range in a domestic refrigerator in order to make power consumption as low as possible while maintaining a given maximum temperature that cannot be exceeded in order to keep the food properly preserved. The refrigerator was modeled as a first order plus time delay system. A hysteretic relay test was used to estimate the system parameters. The system model was employed to develop mathematical relations to set the temperature amplitude inside the refrigerator, given a maximum temperature, in order to minimize the total energy consumption. The model presented indicated that, for the refrigerator studied in this work, the optimal amplitude should be set at approximately 7.5°C, when the refrigerator is loaded with 40 water boxes. Experimental results showed that, using this temperature amplitude resulted in energy consumption 1.7% higher than the best measured value for the same load condition. The model also calculated 9.4°C as the optimal temperature amplitude for the empty refrigerator. With this amplitude, the empty refrigerator consumed the least energy when compared to other tested amplitudes.

Available documents

Format PDF

Pages: 10

Available

  • Public price

    20 €

  • Member price*

    15 €

* Best rate depending on membership category (see the detailed benefits of individual and corporate memberships).

Details

  • Original title: Optimized on-off controller for energy saving in a household refrigerator.
  • Record ID : 30018853
  • Languages: English
  • Source: 2016 Purdue Conferences. 16th International Refrigeration and Air-Conditioning Conference at Purdue.
  • Publication date: 2016/07/11

Links


See other articles from the proceedings (274)
See the conference proceedings

Indexing