Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Alternative

Operation of Mosul – Dokan Reservoirs and Samarra Barrage Using HEC – ResSim Model During Dry Period

Thabet M. Abdulateef; Raad H. Irzooki; Ali S. Abbas

Engineering and Technology Journal, 2021, Volume 39, Issue 8, Pages 1273-1280
DOI: 10.30684/etj.v39i8.1991

The issue of time series records containing low inflow than normal, such critical period results in shortage in reservoir storage, thereby reduction in the reservoir's releases that satisfy the demands. When the expected available water is less than the demand, releases may be curtailed, and the reservoir is under stress. This study presents an application of HEC – ResSim model to simulate the operation of Mosul, Dokan Reservoirs, and Samarra Barrage during the dry period 19992000 (modeling of historical data). Simulated results and recorded data were compared in order to, first improve the applicability of the software to simulate reservoir operation by calibrating the model during the period (1990 2000), and the second to identify the similarity and differences between recorded and model result during dry period. The aim of applying this software is to manage the operation of reservoir's system by establishing an operation policy for each reservoir. The simulation plots for Mosul Reservoir, exhibit storage pool elevation within the conservation zone including the ability of release of minimum downstream requirement and the operating Dokan pool reservoir is less than the conservation level. The upstream of Samarra Barrage pool elevation is affected by the look back level with the consideration of normal and minimum operation levels.

Performance of Alternative Refrigerant R431A on Air- Conditioning System under Real Transient Conditions

Haider ali hussen

Engineering and Technology Journal, 2013, Volume 31, Issue 10, Pages 1962-1971

This paper presents the performances of new ozone-friendly refrigerant (R431a) in air-conditioning system were investigated experimentally and compared with R22 under transient conditions.R431a has no ozone depletion potential and very low greenhouse warming potential of less than 43 (ASHRAE Listed,2007)[1].The variation in refrigeration rate of evaporator, work consumption of compressor and heat rejection rate of condenser with time from the start to stop of the air condition system have been examined. Test results showed that the refrigeration rate of evaporator and heat rejection rate of condenser drops almost parallel to each other, both with a decreasing rate with time. The power consumption on the other hand does not increasing much. The coefficient of performance of R431a decreased from rang 8.96 to 9.28% through (5000 sec) at different ambient temperatures. The refrigeration rate of evaporator decreased by 2.69% through 5000 sec at ambient temperature 30 C° for R431a .The heat rejection rate of condenser decreased by 2.34% through 5000 sec at ambient temperature 30 C° for R431a. Results showed that the coefficient of performance of R431a is 14.67 to 20.34% higher than that of R22. Compressor input power of R431a is 8.39 to 14.19% lower than that of R22 at different ambient temperatures.