Exergy analysis of coupling MED-TVC to Neka combined cycle power plant

Freshwater generation is always one of the most important issues in human communities coincided with population increase in different areas, using water desalination technology can be one of the most effective and useful method in utilizing power plants heat recovery. Iran has a high potential to use this technology due to the shortage of fresh water resources on the one hand and several thermal power plants in the coastal areas of North and South on the other hand. In this study, exergy destruction rate in different components of the cycle and also the rate of profit and loss resulting from coupling desalination to Neka power plant were studied according to the project of Caspian Sea water transfer to the central plateau of Iran and the necessity of water desalination before transferring. Results showed that the maximum exergy destruction cost occurred in the thermo-compressor and then in condenser. also if the flow of low pressure turbine used in MED-TVC can product7215m3/day freshwater but this decrease in LP turbine flow, decreased 6.67% of the total power and 0.9 % thermal efficiency of a power plant

Study of the effect of using duct burner on the functional parameters of the two repowered cycles through exergy analysis

Steam power plants have been extensively used in Iran for a long time, yet no specific step has been taken for promoting their performance. In this regard, full repowering is considered as a way to enhance the performance of steam power plants. Furthermore, because of the continental condition of Iran, duct burners can be used as a common strategy to compensate for power generation shortage caused by environmental conditions. In this study, the effect of using a duct burner on the full repowering of Be’sat Steam Cycle representing both single-and dual-pressure cycles was investigated based on exergy analysis. The results showed that by using the duct burner, due to the increase in the heat recovery steam generator inlet gas temperature, the general thermal efficiency of the combined cycle and the exergy efficiency of the combined cycle and heat recovery steam generator decreased. However, the results revealed an increase in the stack temperature and resulting exergy losses, steam flow and power generation

Epidemic size, trend and spatiotemporal mapping of SARS-CoV-2 using geographical information system in Alborz Province, Iran

Abstract Background The first confirmed cases of COVID-19 in Iran were reported in Qom city. Subsequently, the neighboring provinces and gradually all 31 provinces of Iran were involved. This study aimed to investigate the case fatility rate, basic reproductive number in different period of epidemic, projection of daily and cumulative incidence cases and also spatiotemporal mapping of SARS-CoV-2 in Alborz province, Iran. Methods A confirmed case of COVID-19 infection was defined as a case with a positive result of viral nucleic acid testing in respiratory specimens. Serial interval (SI) was fitted by gamma distribution and considered the likelihood-based R0 using a branching process with Poisson likelihood. Seven days average of cases, deaths, doubling times and CFRs used to draw smooth charts. kernel density tool in Arc GIS (Esri) software has been employed to compute hot spot area of the study site. Results The maximum-likelihood value of R0 was 2.88 (95%, CI: 2.57–3.23) in the early 14 days of epidemic. The case fatility rate for Alborz province (Iran) on March 10, was 8.33% (95%, CI:6.3–11), and by April 20, it had an increasing trend and reached 12.9% (95%,CI:11.5–14.4). The doubling time has been increasing from about two days and then reached about 97 days on April 20, 2020, which shows the slowdown in the spread rate of the disease. Also, from March 26 to April 2, 2020 the whole Geographical area of Karj city was almost affected by SARS-CoV-2. Conclusions The R0 of COVID-19 in Alborz province was substantially high at the beginning of the epidemic, but with preventive measures and public education and GIS based monitoring of the cases,it has been reduced to 1.19 within two months. This reduction highpoints the attainment of preventive measures in place, however we must be ready for any second epidemic waves during the next months