The Experts below are selected from a list of 45096 Experts worldwide ranked by ideXlab platform
Hadi Rostamzadeh - One of the best experts on this subject based on the ideXlab platform.
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comparative study of two novel micro cchp systems based on organic rankine cycle and kalina cycle
Energy Conversion and Management, 2019Co-Authors: Hadi Rostamzadeh, Hadi Ghaebi, Mohammad Ebadollahi, Afshar ShokriAbstract:Abstract With regard to the significant role of combined cooling, heating, and power (CCHP) systems in performance enhancement of power plants, two novel micro-CCHP systems are presented which are based on organic Rankine cycle (ORC) and Kalina cycle (KC) as topping cycles. Additionally, ejector refrigeration cycle (ERC) and vapor compression heat pump cycle (VCHPC) are utilized as the bottoming cycle of the power systems. To demonstrate feasibility of the recommended micro-CCHP systems, an exhaustive thermodynamic modeling and exergoeconomic analysis are employed as the most effective tools for performance evaluation of the systems. Also, to get better performance of the systems, single- and multi-criteria optimizations are carried out, using genetic algorithm. It is figured out that the KC-based micro-CCHP system has higher optimum thermal efficiency and total sum unit cost of the product (SUCP) than the ORC-based micro-CCHP system, while it had lower exergy efficiency. Regarding that, the optimum thermal efficiency for the ORC- and KC-based micro-CCHP systems are computed by 76.54% and 77.32%, respectively, whilst the optimum exergy efficiency for the ORC- and KC-based micro-CCHP systems are calculated by 48.37% and 31.2%, respectively. In addition, generator had the major exergy destruction rate among all components for both systems. Furthermore, the results of parametric study proved that higher thermal (energy) efficiency can be computed with increasing the heat source Temperature, heater Temperature, evaporation Temperature, and Terminal Temperature difference of the recovery heat exchangers.
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performance assessment and optimization of a humidification dehumidification hdh system driven by absorption compression heat pump cycle
Desalination, 2018Co-Authors: Hadi Rostamzadeh, Amin Shekari Namin, Hadi Ghaebi, Majid AmidpourAbstract:Abstract Feasibility investigation of a humidification dehumidification (HDH) desalination system driven by an absorption-compression heat pump cycle (ACHPC) is carried out in this paper. The proposed hybrid desalination system uses both heating capacity of the discharged brine as a waste heat for the ACHPC and mechanical power of the ACHPC for the HDH system. The system's performance is investigated under different optimal design modes, using genetic algorithm (GA) as the most robust tool for optimization. A steady-state mathematical model based on the mass, energy, exergy, and exergoeconomic balance equations for components of the proposed system is developed and the predicted results are validated using the available experimental and numerical data. The results indicated that the proposed hybrid system can produce the maximum freshwater of 0.647 kg/s with the gain output ratio (GOR) and exergy-based GOR (EGOR) of 9.02 and 3.04%, respectively. In this optimal mode, the cost of produced freshwater and specific work consumption (SW) are estimated 7.13 $/l and 262.9, respectively. Furthermore, a comprehensive parametric study is conducted leading to the determination of the proposed system's behavior due to any variation in the key thermodynamic parameters. It is found that the GOR and EGOR can be maximized with the desalination top Temperature, desalination mass flowrate ratio, and compression ratio, while the cost of freshwater can be minimized with the absorber Terminal Temperature difference and compression ratio. At last, multi-variable regression analysis is employed to correlate the main performance criteria of the system with the key thermodynamic parameters.
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proposal and assessment of a novel geothermal combined cooling and power cycle based on kalina and ejector refrigeration cycles
Applied Thermal Engineering, 2018Co-Authors: Hadi Ghaebi, Hadi Rostamzadeh, Towhid Parikhani, Behzad FarhangAbstract:Abstract This paper aims at introducing a new combined cooling and power (CCP) cycle, using geothermal energy as low-Temperature heat source. The proposed cycle is integrated from a Kalina cycle (KC) and an ejector refrigeration cycle (ERC) to produce a simultaneous refrigeration and power outputs. To enhance performance operation of the proposed CCP cycle, turbine exhaust is extracted for more power production purposes by employing a feed fluid heater (FFH). Energy and exergy assessments of the proposed CCP cycle are conducted using Engineering Equation Solver (EES) software. In addition, considering the thermal efficiency and exergy efficiency as objective functions, single- and multi-objective optimizations are carried out by genetic algorithm (GA), leading to determination of the optimum design variables including basic ammonia concentration, geothermal inlet Temperature, evaporator Temperature, turbine inlet pressure, mass extraction ratio (MER), FFH pressure, Terminal Temperature difference (TTD) of vapor generator, and pinch point Temperature differences of vapor generator and recuperators. In this case, the optimum net output power, refrigeration, thermal efficiency and exergy efficiency are calculated 2319 kW, 1133 kW, 15% and 47.8%, respectively. Moreover, among all components condenser 1 accounts for the biggest exergy destruction rate (589.6 kW) followed by vapor generator (422.1 kW). To better understand the effect of various parameters on system performance, a comprehensive parametric study of some key parameters (including turbine inlet pressure, geothermal inlet Temperature, feed fluid heater pressure, evaporator Temperature, basic ammonia concentration, and mass extraction ratio) on the performance criteria is carried out. It is shown that the exergy efficiency of system can be maximized based on the turbine inlet pressure, feed fluid heater pressure, basic ammonia concentration, and mass extraction ratio. In addition, the thermal efficiency of system can be maximized by feed fluid heater pressure, while refrigeration output can be maximized by mass extraction ratio. Also, it is shown that a higher power output can be obtained at lower turbine inlet and feed fluid heater pressures as well as higher geothermal inlet Temperature, basic ammonia concentration, and mass extraction ratio. Moreover, a higher refrigeration output can be resulted at higher turbine inlet pressure and evaporator Temperature, as well as lower feed fluid heater pressure and basic ammonia concentration.
Keyi Zhou - One of the best experts on this subject based on the ideXlab platform.
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research on varying condition characteristic of feedwater heater considering liquid level
Applied Thermal Engineering, 2014Co-Authors: Jianqun Xu, Tao Yang, Keyi ZhouAbstract:Abstract In this paper, a mathematical model of varying condition is established for the three-section heater based on dimensional analysis, then with the combination of the derivation of heat transfer coefficient in the drain cooler section, the model of operating characteristic for the heater at low liquid level is proposed. Taking #1 high pressure feedwater heater of a 330 MW turbine as example, the Terminal Temperature difference at both normal liquid level and low liquid level and the change of the heat transfer condition in the drain cooler section at low liquid level can be calculated respectively by the proposed model. By comparison with the test data the accuracy of the model is verified. In addition, the influence of liquid level and load on Terminal Temperature difference is analyzed quantitatively, and the secure liquid level and economic liquid level are reset. The results show that the study can provide a reference for the timely adjustment of the liquid level in actual operation.
Bimala P. Baruah - One of the best experts on this subject based on the ideXlab platform.
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production and characterization of bio oil produced from ipomoea carnea bio weed
Bioenergy Research, 2015Co-Authors: Prasenjit Saikia, Rupam Kataki, Upendra Nath Gupta, Rajiyung S Barman, Rahul Singh Chutia, Bimala P. BaruahAbstract:Bio-energy is now emerging as a future source of energy. Pyrolysis is one of the main thermo-chemical processes that can provide a useful and valuable bio-fuel such as bio-oil and bio-char. Bio-oil was produced from an undesired bio-weed named Ipomoea carnea by thermal pyrolysis at a Terminal Temperature range from 350 to 600 °C with a heating rate of 10 °C/min. Maximum bio-oil yield (41.17 % of which 11.45 % is the oil phase) was obtained at a pyrolysis Temperature of 550 °C. The oil obtained was characterized by Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR; 1H and 13C), and gas chromatography–mass spectroscopy (GC-MS) which revealed the presence of various hydrocarbons and alcohols. The H/C molar ratio (1.49) of the bio-oil was found to be comparable with petroleum-derived diesel. However, the presence of oxygen (35.86 %) in the form of oxygenates especially organic acids make the bio-oil acidic, which needs to be upgraded to use in the current IC engine.
Hadi Ghaebi - One of the best experts on this subject based on the ideXlab platform.
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comparative study of two novel micro cchp systems based on organic rankine cycle and kalina cycle
Energy Conversion and Management, 2019Co-Authors: Hadi Rostamzadeh, Hadi Ghaebi, Mohammad Ebadollahi, Afshar ShokriAbstract:Abstract With regard to the significant role of combined cooling, heating, and power (CCHP) systems in performance enhancement of power plants, two novel micro-CCHP systems are presented which are based on organic Rankine cycle (ORC) and Kalina cycle (KC) as topping cycles. Additionally, ejector refrigeration cycle (ERC) and vapor compression heat pump cycle (VCHPC) are utilized as the bottoming cycle of the power systems. To demonstrate feasibility of the recommended micro-CCHP systems, an exhaustive thermodynamic modeling and exergoeconomic analysis are employed as the most effective tools for performance evaluation of the systems. Also, to get better performance of the systems, single- and multi-criteria optimizations are carried out, using genetic algorithm. It is figured out that the KC-based micro-CCHP system has higher optimum thermal efficiency and total sum unit cost of the product (SUCP) than the ORC-based micro-CCHP system, while it had lower exergy efficiency. Regarding that, the optimum thermal efficiency for the ORC- and KC-based micro-CCHP systems are computed by 76.54% and 77.32%, respectively, whilst the optimum exergy efficiency for the ORC- and KC-based micro-CCHP systems are calculated by 48.37% and 31.2%, respectively. In addition, generator had the major exergy destruction rate among all components for both systems. Furthermore, the results of parametric study proved that higher thermal (energy) efficiency can be computed with increasing the heat source Temperature, heater Temperature, evaporation Temperature, and Terminal Temperature difference of the recovery heat exchangers.
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performance assessment and optimization of a humidification dehumidification hdh system driven by absorption compression heat pump cycle
Desalination, 2018Co-Authors: Hadi Rostamzadeh, Amin Shekari Namin, Hadi Ghaebi, Majid AmidpourAbstract:Abstract Feasibility investigation of a humidification dehumidification (HDH) desalination system driven by an absorption-compression heat pump cycle (ACHPC) is carried out in this paper. The proposed hybrid desalination system uses both heating capacity of the discharged brine as a waste heat for the ACHPC and mechanical power of the ACHPC for the HDH system. The system's performance is investigated under different optimal design modes, using genetic algorithm (GA) as the most robust tool for optimization. A steady-state mathematical model based on the mass, energy, exergy, and exergoeconomic balance equations for components of the proposed system is developed and the predicted results are validated using the available experimental and numerical data. The results indicated that the proposed hybrid system can produce the maximum freshwater of 0.647 kg/s with the gain output ratio (GOR) and exergy-based GOR (EGOR) of 9.02 and 3.04%, respectively. In this optimal mode, the cost of produced freshwater and specific work consumption (SW) are estimated 7.13 $/l and 262.9, respectively. Furthermore, a comprehensive parametric study is conducted leading to the determination of the proposed system's behavior due to any variation in the key thermodynamic parameters. It is found that the GOR and EGOR can be maximized with the desalination top Temperature, desalination mass flowrate ratio, and compression ratio, while the cost of freshwater can be minimized with the absorber Terminal Temperature difference and compression ratio. At last, multi-variable regression analysis is employed to correlate the main performance criteria of the system with the key thermodynamic parameters.
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proposal and assessment of a novel geothermal combined cooling and power cycle based on kalina and ejector refrigeration cycles
Applied Thermal Engineering, 2018Co-Authors: Hadi Ghaebi, Hadi Rostamzadeh, Towhid Parikhani, Behzad FarhangAbstract:Abstract This paper aims at introducing a new combined cooling and power (CCP) cycle, using geothermal energy as low-Temperature heat source. The proposed cycle is integrated from a Kalina cycle (KC) and an ejector refrigeration cycle (ERC) to produce a simultaneous refrigeration and power outputs. To enhance performance operation of the proposed CCP cycle, turbine exhaust is extracted for more power production purposes by employing a feed fluid heater (FFH). Energy and exergy assessments of the proposed CCP cycle are conducted using Engineering Equation Solver (EES) software. In addition, considering the thermal efficiency and exergy efficiency as objective functions, single- and multi-objective optimizations are carried out by genetic algorithm (GA), leading to determination of the optimum design variables including basic ammonia concentration, geothermal inlet Temperature, evaporator Temperature, turbine inlet pressure, mass extraction ratio (MER), FFH pressure, Terminal Temperature difference (TTD) of vapor generator, and pinch point Temperature differences of vapor generator and recuperators. In this case, the optimum net output power, refrigeration, thermal efficiency and exergy efficiency are calculated 2319 kW, 1133 kW, 15% and 47.8%, respectively. Moreover, among all components condenser 1 accounts for the biggest exergy destruction rate (589.6 kW) followed by vapor generator (422.1 kW). To better understand the effect of various parameters on system performance, a comprehensive parametric study of some key parameters (including turbine inlet pressure, geothermal inlet Temperature, feed fluid heater pressure, evaporator Temperature, basic ammonia concentration, and mass extraction ratio) on the performance criteria is carried out. It is shown that the exergy efficiency of system can be maximized based on the turbine inlet pressure, feed fluid heater pressure, basic ammonia concentration, and mass extraction ratio. In addition, the thermal efficiency of system can be maximized by feed fluid heater pressure, while refrigeration output can be maximized by mass extraction ratio. Also, it is shown that a higher power output can be obtained at lower turbine inlet and feed fluid heater pressures as well as higher geothermal inlet Temperature, basic ammonia concentration, and mass extraction ratio. Moreover, a higher refrigeration output can be resulted at higher turbine inlet pressure and evaporator Temperature, as well as lower feed fluid heater pressure and basic ammonia concentration.
Joh H Lienhard - One of the best experts on this subject based on the ideXlab platform.
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optimal operating conditions and configurations for humidification dehumidification desalination cycles
International Journal of Thermal Sciences, 2011Co-Authors: Kara H Mistry, Alexande Mitsos, Joh H LienhardAbstract:Abstract This article applies nonlinear programming techniques to optimize humidification–dehumidification (HD) desalination cycles for operating conditions that result in maximum gained output ratio (GOR). Closed air open water as well as open air open water cycles, each with either an air or a water heater, were considered in this analysis. Numerical optimization resulted in a substantial increase in GOR for all four cycle types compared to previous best-case conditions found using heuristic studies. The GOR of the cycles was found to decrease with increasing component Terminal Temperature difference (TTD). In addition, different cycles perform best at different Temperature differences. Optimization also revealed that some counterintuitive design configurations can result in superior performance under the appropriate operating conditions.
