| Autor: |
Тітлов, О. С., Осадчук, Є. О., Цой, О. П., Алімкешова, А. Х., Джамашева, Р. А. |
| Zdroj: |
Refrigeration Engineering & Technology; 2019, Vol. 55 Issue 2, p84-96, 13p |
| Abstrakt: |
The analysis of the possibilities of using night radiation cooling (NRC) for additional heat removal from the elements of the liquid cooling system was performed. The energy prospects of using NRC technology for autonomous primary cooling systems mainly in rural and peasant farms located in remote areas from sources of electrical energy are shown. To improve the energy efficiency of autonomous cooling systems, it was proposed to use absorption water-ammonia refrigerator (AWAR) and compression refrigerator (CR), which will allow to create cold reserves in the cold-accumulation system during daylight hours. To work AWAR proposed to use thermal energy of solar radiation. A methodology for modeling the AWAR modes has been developed and an analysis of the results obtained in a wide range of operating thermodynamic parameters (ambient temperature – 17…47 °C, temperature of the cooling object -minus 30…15 °C). The methodology is based on the original algorithm for finding the minimum required temperature of the heating medium, depending on the temperature of the cooling object and the cooling medium of the real AWAR. It is shown that when implementing traditional AWAR cycles, there are regimes with maximum energy efficiency, and to achieve them, an appropriate combination of working fluid composition (water-ammonia solution) and temperature of the heating source is required. It is also shown that when working from solar collectors with water as a coolant, it is necessary to include a booster-compressor in front of the ammonia condenser in the AWAR circuit. A thermodynamic analysis of CR cycles operating on currently approved working bodies was performed. High energy characteristics of CR are noted when operating at low ambient temperatures. Thus, with a decrease in the temperature of atmospheric air from 40 °C to 10 °C, on average, there is an increase in the refrigeration coefficient of cycles of CR by 4-6 times, and for ammonia -by 17.3 times. Original schemes of primary milk cooling systems based on CR and AWAR using NRC technology have been developed, which allow working in autonomous mode using the minimum amount of electrical energy. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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