Energy, Exergy, Exergoeconomic and Exergoenvironmental Impact Analyses and Optimization of Various Geothermal Power Cycle Configurations

Energy, exergy, and exergoeconomic evaluations of various geothermal configurations are reported. The main operational and economic parameters of the cycles are evaluated and compared. Multi-objective optimization of the cycles is conducted using the artificial bee colony algorithm. A sensitivity assessment is carried out on the effect of production well temperature variation on system performance from energy and economic perspectives. The results show that the flash-binary cycle has the highest thermal and exergy efficiencies, at 15.6% and 64.3%, respectively. The highest generated power cost and pay-back period are attributable to the simple organic Rankine cycle (ORC). Raising the well-temperature can increase the exergy destruction rate in all configurations. However, the electricity cost and pay-back period decrease. Based on the results, in all cases, the exergoenvironmental impact improvement factor decreases, and the temperature rises. The exergy destruction ratio and efficiency of all components for each configuration are calculated and compared. It is found that, at the optimum state, the exergy efficiencies of the simple organic Rankine cycle, single flash, double flash, and flash-binary cycles respectively are 14.7%, 14.4%, 12.6%, and 14.1% higher than their relevant base cases, while the pay-back periods are 10.6%, 1.5% 1.4%, and 0.6% lower than the base cases.

Improving the efficiency of autonomous electrical complexes of oil and gas enterprises

In accordance with the Energy Strategy until 2035, the possibility of increasing the efficiency of energy use of secondary energy resources in the form of associated oil and waste gases has been substantiated by increasing the energy efficiency of the primary energy carrier to 90-95 % by means of cogeneration plants with a binary cycle of electricity generation and trigeneration systems with using the energy of the waste gas to cool the air flow at the inlet of gas turbine plants. The conditions for maintaining the rated power of the main generator with variations in the ambient temperature are shown. An effective topology of electrical complexes in a multi-connected power supply system of oil and gas enterprises according to the reliability condition is presented, which allows increasing the availability factor by 0.6 %, mean time between failures by 33 %, the probability of failure-free operation by 15 % and reducing the mean time of system recovery by 40 %. The article considers the use of parallel active filters to improve the quality of electricity and reduce voltage drops to 0.1 s when used in autonomous electrical complexes of oil and gas enterprises. The possibility of providing uninterrupted power supply when using thyristor systems for automatic reserve input has been proven. A comparative analysis was carried out to assess the effect of parallel active filters and thyristor systems of automatic transfer of reserve on the main indicators of the reliability of power supply systems of oil and gas enterprises.

Utilization Waste Brine Water Separator for Binary Electric Energy Conversion in Geothermal Wells

Nowadays, geothermal is one of the most environmentally friendly energy that can replace the role of fossils energy by converting steam to electricity. Brine is one of the by-products of the production of geothermal wells that are generally not used or simply re-injected. In fact, brine can be converted into electricity using the binary cycle process. In binary cycle, brine from separator is used as a heater of working fluid and transform it into a vapor phase. The vapor will be used to turn turbines and generators to produce electricity. The working fluid selection in accordance with the heating fluid temperature becomes important because it results in optimization of the thermodynamic cycle. The temperature of the wellhead in the geothermal field will decrease 3% per year and reducing the heating fluid temperature in heat exchanger. So, in this paper intends to utilizes brine to heat the heat exchanger by using iso-butane, n-pentane, and iso-pentane because its critical temperature can be stable at 193℃ wellhead temperatures. From the results of predictions from brain 2 production well for 17 years with iso-butane in this binary cycle planning, can utilize waste brine water separator to converse electric energy to produce 4 MWh electricity.

Agent-Based Simulation with Data-Driven Parameterization for Evaluation of Social Acceptance of a Geothermal Development

Development of geothermal power plants and local geothermal energy initiatives have lagged due to the social problems such as conflicts with stakeholders such as Onsen (Hot Spa) owners, despite the abundant geothermal resources. Study area was Tsuchiyu Onsen in Fukushima prefecture, Tohoku (Northeast) District, Japan, where the Great East Japan Earthquake and Fukushima Nuclear Accident occurred in 2011, and the reconstruction and local initiatives of geothermal energy were still unclear. Agent-based modeling (ABM) is an effective methodology for modeling and analysis of opinion formation. Parameter estimation method was proposed to extract appropriate parameters from various factors through a Bayesian Network. The characteristics of stakeholders and communities that affected opinion formation in the survey area were successfully extracted. Here we show the sufficient methodology to quantify the characteristics of each person using survey data, and to extract the parameters of the agent by data-driven inverse analysis. By using this methodology, we could reproduce opinion diversity, which is a property of opinion formation in real communities. This result suggests that the model replicates the actual formation of opinion in Tsuchiyu, where the economy was boosted by the construction of a binary cycle power plant.

The gender-binary cycle: the perpetual relations between a biological-essentialist view of gender, gender ideology, and gender-labelling and sorting

Gender inequality is one of the most pressing issues of our time. A core factor that feeds gender inequality is people's gender ideology—a set of beliefs about the proper order of society in terms of the roles women and men should fill. We argue that gender ideology is shaped, in large parts, by the way people make sense of gender differences. Specifically, people often think of gender differences as expressions of a predetermined biology, and of men and women as different ‘kinds’. We describe work suggesting that thinking of gender differences in this biological-essentialist way perpetuates a non-egalitarian gender ideology. We then review research that refutes the hypothesis that men and women are different ‘kinds’ in terms of brain function, hormone levels and personality characteristics. Next, we describe how the organization of the environment in a gender-binary manner, together with cognitive processes of categorization drive a biological-essentialist view of gender differences. We then describe the self-perpetuating relations, which we term the gender-binary cycle , between a biological-essentialist view of gender differences, a non-egalitarian gender ideology and a binary organization of the environment along gender lines. Finally, we consider means of intervention at different points in this cycle. This article is part of the theme issue ‘The political brain: neurocognitive and computational mechanisms’.

Exploitation assessment of geothermal energy from African Great Rift Valley

Countries that are in the Great Rift Valley have one of the lowest average annual electricity consumption per capita in Africa with a value of 164 kWh per inhabitant. Furthermore, the electrification rate is 34% that is more than fifty percentage points below the world average, which is around 86%. One possible solution to improve the electrification rate is to properly exploit the energy resources present in the territory. One of the most significant energy sources of this region is certainly geothermal energy which has a potential of about 15 GWe, mostly concentrated in Ethiopia. Furthermore, it is possible to find the resource in a wide temperature range, not only to produce electricity, which, nonetheless, has a very limited exploitation rate, as only 900 MWe are installed between Kenya and Ethiopia, but also for direct use. In this study, two geothermal power plants for two different geothermal sites, Corbetti and Arus-Bogoria, respectively in Ethiopia and Kenya, have been hypothesized after analyzing the resource potential. For the first, which has been estimated to be of high enthalpy (~300°C), a flash plant configuration was assumed, and the estimated energy production potential was found to be around 50-100 MWe. While for the second, at medium enthalpy (T<200°C), the use of a binary cycle plant was assumed with an obtained production of about 20 MW of electricity. Finally, the possibility of geothermal water exploitation for greenhouse heating, drying of agricultural products, civil sanitary uses, recreational uses (spa), or for industrial purposes has been assessed.

Geothermal energy in Germany

Geothermal energy is a significant source of renewable power. In Germany, geothermal technology incorporates a wide range of solutions as shown in this paper. Briefly, this technology is generally based on geothermal loop systems with double wells. There are also five well heat exchanger geothermal systems and two shaft water geothermal systems operating in Germany. Eleven geothermal power plants of 21.8 MW in sum are binary cycle operated and using coolants. Four of them generate electric power while seven cogenerate electric power and heat.

The Gender-Binary Cycle

Gender inequality is one of the most pressing issues of our time. A core factor that feeds gender inequality is people’s gender ideology - a set of beliefs about the proper order of society in terms of the roles women and men should fill. We argue that gender ideology is shaped, in large parts, by the way people make sense of gender differences. Specifically, people often think of gender differences as expressions of a predetermined biology, and of men and women as different "kinds". We describe work suggesting that thinking of gender differences in this biological-essentialist way perpetuates a non-egalitarian gender ideology. We then review research that refutes the hypothesis that men and women are different "kinds" in terms of brain function, hormone levels, and personality characteristics. Next, we describe how the organization of the environment in a gender-binary manner, together with cognitive processes of categorization drive a biological-essentialist view of gender differences. We then describe the self-perpetuating relations, which we term the gender-binary cycle, between a biological-essentialist view of gender differences, a non-egalitarian gender ideology, and a binary organization of the environment along gender lines. Finally, we consider means of intervention at different points in this cycle.

Potential Conceptual Developments for the Improvement of Transport Internal Combustion Engines

New conceptual solutions are required to significantly improve combustion engine efficiency. For example, the use of the outboard spool combustion chamber of constant volume and the separation of the compression and expansion processes in the internal combustion engine can provide multi-fuel capability, a significant increase in efficiency and an opportunity to exclude or significantly simplify the gear box. The implementation of a binary cycle including heat loss recovery in two additional strokes supporting the steam cycle increases efficiency and solves the cooling problem of the combustion engine. The binary cycle is most effective in air-independent power plants of underwater objects with a limited reserve of oxidizers. The presence of a separate oxidizer makes it possible to achieve high capacity by increasing the simultaneous supply of oxidant, fuel and water to the steam part of the cycle. In order to qualitatively improve the characteristics of the combustion engine, a system analysis of the developed technical solutions is also required, followed by an integrated implementation.