scholarly journals Thermodynamic assessment of a cogeneration system with CSP Driven-Brayton and Rankine cycles for electric power and hydrogen production in the framework of the energy and water nexus

Energy Nexus ◽  
2021 ◽  
pp. 100031
Author(s):  
Ehsanolah Assareh ◽  
Mohammad Assareh ◽  
Seyed Mojtaba Alirahmi ◽  
Milad Shayegh ◽  
Fuqiang Wang ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Electric Power ◽  
Thermodynamic Assessment ◽  
Cogeneration System

Hydrogen production from methane reforming: Thermodynamic assessment and autothermal reactor design

2009 ◽  
Vol 1 (6) ◽  
pp. 205-215 ◽  
Author(s):  
C.N. Ávila-Neto ◽  
S.C. Dantas ◽  
F.A. Silva ◽  
T.V. Franco ◽  
L.L. Romanielo ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Thermodynamic Assessment ◽  
Reactor Design ◽  
Methane Reforming

scholarly journals Energy-Saving and CO2-Emissions-Reduction Potential of a Fuel Cell Cogeneration System for Condominiums Based on a Field Survey

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6611
Author(s):  
Kazui Yoshida ◽  
Hom B. Rijal ◽  
Kazuaki Bohgaki ◽  
Ayako Mikami ◽  
Hiroto Abe
Keyword(s):  
Power Generation ◽  
Energy Consumption ◽  
Fuel Cell ◽  
Energy Saving ◽  
Electric Power ◽  
Water Use ◽  
Co2 Emission ◽  
Contribution Rate ◽  
Electric Power Generation ◽  
Cogeneration System

A residential cogeneration system (CGS) is highlighted because of its efficient energy usage on both the supplier and consumer sides. It generates electricity and heat simultaneously; however, there is insufficient information on the efficiency according to the condition of usage. In this study, we analysed the performance data measured by the home energy management system (HEMS) and the lifestyle data of residents in a condominium of 356 flats where fuel cell CGS was installed in each flat. The electricity generated by CGS contributed to an approximately 12% reduction in primary energy consumption and CO2 emission, and the rate of generation by the CGS in the electric power demand (i.e., contribution rate) was approximately 38%. The electricity generation was mainly affected by the use of electricity up to 4 MWh/household/year. Gas or water use also impacted electric power generation, with water use as the primary factor affecting the contribution rate. Electric power generation changes monthly, mainly based on the water temperature. From these results, we confirmed that a CGS has substantial potential to reduce energy consumption and CO2 emission in condominiums. Thus, it is recommended for installation of fuel cell CGS in existing and new buildings to contribute to the energy-saving target of the Japanese Government in the residential sector.

Thermodynamic analysis of a wall mounted gas boiler with an organic Rankine cycle and hydrogen production unit

2017 ◽  
Vol 28 (7) ◽  
pp. 725-743 ◽  
Author(s):  
Anahita Moharamian ◽  
Saeed Soltani ◽  
Faramarz Ranjbar ◽  
Mortaza Yari ◽  
Marc A Rosen
Keyword(s):  
Hydrogen Production ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Inlet Pressure ◽  
Pinch Point ◽  
Working Fluids ◽  
Turbine Inlet ◽  
Energy And Exergy ◽  
Cogeneration System ◽  
Net Power Output

A novel cogeneration system based on a wall mounted gas boiler and an organic Rankine cycle with a hydrogen production unit is proposed and assessed based on energy and exergy analyses. The system is proposed in order to have cogenerational functionality and assessed for the first time. A theoretical research approach is used. The results indicate that the most appropriate organic working fluids for the organic Rankine cycle are HFE700 and isopentane. Utilizing these working fluids increases the energy efficiency of the integrated wall mounted gas boiler and organic Rankine cycle system by about 1% and the organic Rankine cycle net power output about 0.238 kW compared to when the systems are separate. Furthermore, increasing the turbine inlet pressure causes the net power output, the organic Rankine cycle energy and exergy efficiencies, and the cogeneration system exergy efficiency to rise. The organic Rankine cycle turbine inlet pressure has a negligible effect on the organic Rankine cycle mass flow rate. Increasing the pinch point temperature decreases the organic Rankine cycle turbine net output power. Finally, increasing the turbine inlet pressure causes the hydrogen production rate to increase; the highest and lowest hydrogen production rates are observed for the working fluids for HFE7000 and isobutane, respectively. Increasing the pinch point temperature decreases the hydrogen production rate. In the cogeneration system, the highest exergy destruction rate is exhibited by the wall mounted gas boiler, followed by the organic Rankine cycle evaporator, the organic Rankine cycle turbine, the organic Rankine cycle condenser, the proton exchange membrane electrolyzer, and the organic Rankine cycle pump, respectively.

scholarly journals Analysis of a High Temperature Gas-Cooled Reactor Powered High Temperature Electrolysis Hydrogen Plant

2010 ◽  
Author(s):  
M. G. McKellar ◽  
E. A. Harvego ◽  
A. M. Gandrik
Keyword(s):  
High Temperature ◽  
Hydrogen Production ◽  
Economic Analysis ◽  
Electric Power ◽  
Production Rate ◽  
Production Plant ◽  
System Pressure ◽  
Reference Design ◽  
High Temperature Gas ◽  
High Temperature Electrolysis

An updated reference design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production has been developed. The HTE plant is powered by a high-temperature gas-cooled reactor (HTGR) whose configuration and operating conditions are based on the latest design parameters planned for the Next Generation Nuclear Plant (NGNP). The current HTGR reference design specifies a reactor power of 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 322°C and 750°C, respectively. The reactor heat is used to produce heat and electric power for the HTE plant. A Rankine steam cycle with a power conversion efficiency of 44.4% was used to provide the electric power. The electrolysis unit used to produce hydrogen includes 1.1 million cells with a per-cell active area of 225 cm2. The reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes a steam-sweep system to remove the excess oxygen that is evolved on the anode (oxygen) side of the electrolyzer. The overall system thermal-to-hydrogen production efficiency (based on the higher heating value of the produced hydrogen) is 42.8% at a hydrogen production rate of 1.85 kg/s (66 million SCFD) and an oxygen production rate of 14.6 kg/s (33 million SCFD). An economic analysis of this plant was performed with realistic financial and cost estimating The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a competitive cost. A cost of $3.03/kg of hydrogen was calculated assuming an internal rate of return of 10% and a debt to equity ratio of 80%/20% for a reactor cost of $2000/kWt and $2.41/kg of hydrogen for a reactor cost of $1400/kWt.

scholarly journals Hydrogen production through water splitting at low temperature over Fe3O4 pellet: Effects of electric power, magnetic field, and temperature

2021 ◽  
Vol 211 ◽  
pp. 106606
Author(s):  
Despina Karatza ◽  
Christos Konstantopoulos ◽  
Simeone Chianese ◽  
Spyros Diplas ◽  
Peter Svec ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Hydrogen Production ◽  
Electric Power ◽  
Water Splitting

A Comparison of the Predicted and Measured Thermodynamic Performance of a Gas Turbine Cogeneration System

1987 ◽  
Vol 109 (1) ◽  
pp. 32-38 ◽  
Author(s):  
J. W. Baughn ◽  
R. A. Kerwin
Keyword(s):  
Electric Power ◽  
Gas Turbine ◽  
Computer Model ◽  
Measurement Techniques ◽  
Actual Performance ◽  
Fuel Flow ◽  
Savings Rate ◽  
Thermodynamic Performance ◽  
Cogeneration System ◽  
Steam Production

The thermodynamic performance of a gas turbine cogeneration system is predicted using a computer model. The predicted performance is compared to the actual performance, determined by measurements, in terms of various thermodynamic performance parameters which are defined and discussed in this paper. These parameters include the electric power output, fuel flow rate, steam production, electrical efficiency, steam efficiency, and total plant efficiency. Other derived parameters are the net heat rate, the power-to-heat ratio, and the fuel savings rate. This paper describes the cogeneration plant, the computer model, and the measurement techniques used to determine each of the necessary measurands. The predicted and the measured electric power compare well. The predicted fuel flow and steam production are less than measured. The results demonstrate that this type of comparison is needed if computer models are to be used successfully in the design and selection of cogeneration systems.

Effect of Increasing Number of Residential SOFC Cogeneration Systems Involved in Power Interchange Operation in Housing Complex on Energy Saving

2011 ◽  
Vol 8 (4) ◽  
Author(s):  
Tetsuya Wakui ◽  
Ryohei Yokoyama
Keyword(s):  
Energy Saving ◽  
Electric Power ◽  
Power Flow ◽  
Electric Power System ◽  
Mixed Integer ◽  
Load Factor ◽  
Power Demand ◽  
Cogeneration System ◽  
Housing Complex ◽  
Saving Effect

Residential solid oxide fuel cell cogeneration systems (R-FCGSs) have high generating efficiencies; however, they must be operated continuously because of their long warm-up times. Moreover, a reverse power flow from a residential cogeneration system to a commercial electric power system is not permitted in Japan. Because of these restrictions, it is considered that the R-FCGSs may not fully achieve their potential energy-saving effects in Japan. In order to improve the energy-saving effect of the R-FCGSs, the authors have been focusing on a power interchange operation using multiple R-FCGSs (IC) installed at residences in a housing complex as an application of a microgrid. In this operation, the electric power generated by the R-FCGSs is shared among the residences in the housing complex with no reverse power flow so that the electric load factor of the R-FCGSs may increase. This paper discusses the effect of increasing the number of the R-FCGSs involved in the IC on energy saving by conducting optimal operational planning based on mixed-integer linear programming. The numerical analyses for various numbers of target R-FCGSs, with a maximum of 20, clarify that the energy-saving effect of introducing the IC is not correlated with increasing the number of target R-FCGSs, but generally dominated by the total heat to power demand ratio and hourly variations in the electric power demand of the residences. Furthermore, it is revealed that for any number of target R-FCGSs, the IC has an advantage in the energy saving over a stand-alone operation of individual R-FCGSs without the power interchange.

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