Search

Renewable energy use in agricultural applications is essential for sustainable production. Resorption cooling systems can be operated for agricultural cooling applications by using thermal energy derived from geothermal springs with sufficient temperature. Since the resorption cycle uses ammonia-water solution, cold storage and industrial cooling processes below 0°C can be actualized efficiently. In this article, a geothermal powered resorption system for cold storage of apple fruit is investigated. Technical features and cooling performance of the resorption system are analysed and compared to the other conventional cooling systems. Results showed that, geothermal powered resorption cooling systems can annually cover the cooling load of the cold storage application with adequate cooling temperature and capacity. Moreover, the use of the geothermal powered resorption system enables to set up safer and more economic cooling applications with the similar cooling performance compared with the alternative sorption cooling systems, and provides substantial economic benefits by reducing the cooling costs in agricultural production with lower operational costs. [ABSTRACT FROM AUTHOR]

In pandemic periods such as COVID-19, economic and sociological problems threaten human life and public order on a global scale. In these periods, the use of solar powered heating–cooling systems to meet the thermal needs of hospitals and to provide thermal comfort conditions offer important solutions for the elimination of technical, economic and environmental problems related to energy supply. In this study, the heating, cooling and hot water supply of a sample hospital building for the three largest cities of Turkey with a novel solar powered Li-Cl absorption heat pump system was investigated using the Transient System Simulation Tool (TRNSYS) simulation program. The use of a unique NH3-H2O resorption system as a solar powered auxiliary system was also investigated. It was determined that the total annual hot water and cooling needs of the hospital buildings in all three provinces are supplied almost completely by the solar energy powered system without compromising the hygiene and thermal comfort of the occupants. The average annual solar fraction of total heating demands are calculated as 50, 54 and 65% for İstanbul, Ankara and İzmir, respectively. In addition, depending on the use of solar energy, it has been observed that 126 tons of CO2 emissions were saved annually, and an economic saving of 524 375 TL was achieved in total. Considering the problems with energy supply during the epidemic periods, it was concluded that meeting the energy requirements of hospitals with clean, renewable and independent energy source will provide significant benefits to the countries. [ABSTRACT FROM AUTHOR]

A re-circulating heat pump dryer (HPD) system was designed, constructed and tested at steady-state and transient conditions. Refrigerant 134a was used as a refrigerant in this system. The tests were performed to observe behavior of HPD system. So, changes of temperature and relative humidity of drying air through the dryer and heat pump operating temperatures were observed during the drying process and effects of by-pass air ratio (BAR) on the system's parameters as system performance and specific moisture extracted ratio (SMER) at steady-state were investigated. The HPD system was also tested to investigate temperatures and relative humidity changes of drying air during drying process on the system's parameters depend on time. Air flow rate circulated through the HPD system was 554 m3/h during the all tests. According to test results, the system's parameters did not change up to 40% of BAR. Then the coefficient at performance (COP) and SMER values were decreased after 40% of BAR. While SMER values changed between 1.2 and 1.4, COPsys changed between 2.8 and 3.3 depend on BAR. As well as during the drying process, the COP and SMER values were also affected and decreased depend on time. [ABSTRACT FROM AUTHOR]

In this article, solar fraction of energy supply for the annual heating, cooling and domestic hot water requirement of a test room was investigated by using dynamic simulation technique. ClimateWell-Solar Cooling v1.1 build up with TRNSYS simulation programme was used in numerical analysis. The results showed that solar fraction of energy supply for the annual heating, cooling and domestic hot water of the test room are 63%, 99% and 99% respectively. It was obtained that annual average COP for cooling of the absorption system was 0,27 through the cooling period. 1296 TL economic savings and 11974 kg CO2 savings were achieved annually by using solar energy. [ABSTRACT FROM AUTHOR]