Letteratura scientifica selezionata sul tema "GAS TURBINE-HRSG-ORC"

The most effective and environmentally safe fossil fuel power production facilities are the combined cycle gas turbine (CCGT) ones. Electric efficiency of advanced facilities is up to 58% in Russia and up to 64% abroad. The further improvement of thermal efficiency by increase of the gas turbine inlet temperature (TIT) is limited by performance of heat resistance alloys that are used for the hot gas path components and the cooling system efficiency. An alternative method for the CCGT efficiency improvement is utilization of low potential heat of the heat recovery steam generator (HRSG) exhaust gas in an additional cycle operating on a low-boiling heat carrier. This paper describes a thermodynamic analysis of the transition from binary cycles to trinary ones by integration of the organic Rankine cycle (ORC). A mathematical model of a cooled gas turbine plant (GT) has been developed to carry out calculations of high-temperature energy complexes. Based on the results of mathematical modeling, recommendations were made for the choice of the structure and parameters of the steam turbine cycle, as well as the ORC, to ensure the achievement of the maximum thermal efficiency of trinary plants. It is shown that the transition from a single pressure CCGT to a trinary plant allows the electric power increase from 213.4 MW to 222.7 MW and the net efficiency increase of 2.14%. The trinary power facility has 0.45% higher efficiency than the dual pressure CCGT.

Gas turbine cogeneration system integrated with heat recovery steam generator and organic Rankine cycle provides an effective measure of waste heat recovery from exhaust gasses of gas turbine. The numerous study conducted to understand the variation in the performance of the integrated system has been done and the variation of performance with parameters such as turbine inlet temperature, compression ratio mass flow rate etc., has been carried out. The present paper investigates the variation in the performance of the system with change in the surrounding temperature. The paper provides the detailed first law analysis of the system and compares the first law efficiency obtained at different surrounding temperature to justify the location of use of the integrated system.

To rise the thermal efficiency of power generation systems andto meet stricter environmental regulations, improved system inte -gration based on renewable energy is a viable option. In this context,a syngas fuelled Brayton/Rankine combined power cycle integratedwith the Organic Rankine Cycle (ORC) is proposed and analysedfrom both energetic and exergetic point of views. A thermo-chemicalmodel was developed to predict the composition of syngas producedafter biomass gasification, and also, a thermodynamic model wasdeveloped, to determine the energetic and exergetic performance ofthe proposed triple cycle power generation system. We show thatboth first-law and second-law efficiencies of triple power cycle de -creases with the increase in pressure ratio and increases with highergas turbine inlet temperature. It is further shown that first-law andsecond-law efficiencies of solid-waste-derived syngas fuelled triplepower cycle are considerably higher than the rice husk derived syn -gas fuelled cycle. The worst performing components from irrevers-ibility point of view in the proposed triple cycle are the combustor,Heat Recovery Steam Generator (HRSG), and gasifier, respectively.Our results show that integration of ORC with the Biomass-FuelledIntegrated Gasification Combined Cycle (BIGCC) is very effective inimproving the thermal performance of the power plant and in reduc-ing external waste emissions.

The comparative study between the ORC and supercritical ORC has been under study in recent time and the comparatively enhanced performance of the supercritical ORC has made a good alternative to the subcritical ORC systems. In this work, the relative feasibility of the supercritical ORC over ORC was studied when they are positioned as the bottoming cycle in a cogeneration system. A comparative study was carried out to analyse two cogeneration systems, first consisting of Gas Turbine- HRSG-ORC cycle and second consisting of Gas turbine-HRSG-Supercritical ORC cycle. The comparative study was carried out though the energy and exergy analysis of the two systems. Though the energy and exergy analysis it was found that in the bottoming cycle supercritical ORC does performs better in compared to the subcritical ORC. The supercritical ORC register an increase in energy and exergy efficiency by 0.6 to 1.2 percentage point depending upon the value of the parameter taken under the parametric study. However, this comes at the expense of comparatively higher exergy destruction observed in the bottoming supercritical cycle up to certain levels of the parameter. The result also establishes that throughout the parametric range the work output of the bottoming supercritical ORC remains considerably higher than the subcritical ORC cycle.

Abstract In this paper, a combined power and cooling system is thermodynamically analyzed. The system consists of a natural gas-fired gas turbine (GT) plant integrated with a heat recovery steam generator (HRSG), two steam turbines (STs), one organic Rankine cycle (ORC) and two absorption cooling systems (ACSs). With certain given input parameters, the GT plant produces net power of 36.06 MW, the two STs contribute 17.07 MW while from the ORC, 7.18 MW of net power was obtained. From the steam-operated ACS-I, a net 10.36 MW of cooing could be produced. Again, from the GT exhaust operated ACS-II, it was possible to generate additional 3.37 MW of cooling. From exergy analysis, it was found that the total irreversibility was the highest in the GT cycle with a net contribution of 180.412 MW followed by 4.178 MW from the HRSG, 3.561 MW from the ORC, 1.743 MW from ACS-I, 1.186 MW from ST-I, 0.812 MW from ACS-II, 0.175 MW from ST-II. The exergy efficiencies of the GT cycle, ORC, ACS-I and ACS-II were found 22.00%, 65.48%, 18.95% and 14.4% respectively. Regarding the power and cooling output, it can be concluded that these results are specific to the selected operating parameters. Further investigation is required, where, other similar configurations may be considered to make a final comment on the suitability of the proposed configuration from energy output and economic point of view.

Nowadays, the rising demand for energy and serious environmental pollution become the motive to improve the energy structure, saving energy and optimize energy utilization. Based on a gas turbine, a marine multistage gas turbine combined heat and power (CHP) structure is proposed. The CHP system includes the top gas turbine Brayton cycle, the intermediate water Rankine cycle (WRC) and the bottom organic Rankine cycle (ORC). According to the method of screening organic Rankine cycle refrigerant to select the appropriate organic working fluids, and their physical characteristics are described. Based on the modular modelling method, the 3-stage CHP system is established. In order to more effectively absorb low temperature waste heat, three different kinds of 3-stage CHP structures were designed to recover the heat in the exhaust gas from the heat recover steam generator (HRSG). The thermodynamic model of the combined heat and power system of marine multistage gas turbine was used to simulate the performance of three different types of 3-stage CHP structures, the optimal 3-stage CHP structure was selected by comparing and analyzing the simulation results. Based on the simulation results of the design point, it is found that the introduction of the optimal 3-stage CHP structure can increase the power output by about 8.5% and improve the cycle thermal efficiency by about 4.32% compared with a conventional 2-stage CHP cycle where only gas turbine topping cycle and water Rankine bottoming cycle are included.