Fundamental Factors in the Design of a Fast-Responding Methanol-to-Hydrogen Steam Reformer for Transportation Applications

1996 ◽  
Vol 118 (2) ◽  
pp. 112-119 ◽  
Author(s):  
G. L. OhI ◽  
J. L. Stein ◽  
G. E. Smith
Keyword(s):  
Life Cycle ◽  
Power Plant ◽  
Dynamic Response ◽  
Response Time ◽  
Initial Conditions ◽  
Design Parameters ◽  
Maximum Output ◽  
Energy Storage Devices ◽  
Steam Reformer ◽  
Transportation Applications

Improving the dynamic response of the steam reformer in a fuel cell power plant designed for transportation applications will enable the power plant to operate in a transient manner with a reduced need for supplementary batteries and their associated cost, weight, and life cycle limitations. As a method of seeking improvements to the dynamic response, a sixth-order dynamic model of a steam reformer is used with a design optimization process to determine the values of the steam reformer design parameters which will yield the fastest response time to a step input in hydrogen demand under a variety of initial conditions. Results of this analysis suggest that a steam reformer designed to have a maximum output of approximately 12,600 mol/h of hydrogen and optimized for fast response could have response times on the order of 15–20 s. A sensitivity analysis suggests that this response can be achieved primarily by reducing the thermal capacity of the reformer and improving the rate of heat transfer to the gaseous constituents within the reformer. With a steam reformer response time on the order of 15–20 s, supplementary energy storage devices, such as the ultracapacitor and flywheel, become more feasible. These devices are attractive because they have superior life cycle and power density characteristics when compared with traditional chemical batteries.

A Dynamic Model for the Design of Methanol to Hydrogen Steam Reformers for Transportation Applications

2004 ◽  
Vol 126 (2) ◽  
pp. 149-158 ◽  
Author(s):  
Gregory L. Ohl ◽  
Jeffrey L. Stein ◽  
Gene E. Smith
Keyword(s):  
Response Time ◽  
Dynamic Model ◽  
First Principles ◽  
Initial Conditions ◽  
Design Parameters ◽  
Physical Parameters ◽  
Steam Reformer ◽  
Powerful Means ◽  
Steam Reformers ◽  
Transportation Applications

As an aid to improving the dynamic response of the steam reformer, a dynamic model is developed to provide preliminary characterizations of the major constraints that limit the ability of a reformer to respond to the varying output requirements occurring in vehicular applications. This model is a first principles model that identifies important physical parameters in the steam reformer. The model is then incorporated into a design optimization process, where minimum steam reformer response time is specified as the objective function. This tool is shown to have the potential to be a powerful means of determining the values of the steam reformer design parameters that yield the fastest response time to a step input in hydrogen demand for a given set of initial conditions. A more extensive application of this methodology, yielding steam reformer design recommendations, is contained in a related publication.

Soil–Structure–Wave Interaction of Gravity-Based Offshore Wind Turbines: An Analytical Model

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Dimitrios G. Pavlou
Keyword(s):  
Dynamic Response ◽  
Analytical Model ◽  
Wind Turbines ◽  
Initial Conditions ◽  
Offshore Wind ◽  
Design Parameters ◽  
Wave Loads ◽  
Wave Load ◽  
Offshore Wind Turbines ◽  
Dynamic Phenomena

Abstract The structural design of offshore wind turbines is based on the consideration of coupled dynamic phenomena. Wave loads cause the dynamic oscillation of the monopile, and the dynamic oscillation of the monopile affects the wave loads. The boundary conditions of the gravity-based foundation-monopile-turbine system are mostly affected by the flexural stiffness of the foundation plate, the elastic and creep behavior of the soil, and the inertia (translational and rotational) of the wind turbine mass. The design of the foundation should consider the dynamic response of the soil and the monopile, and the dynamic response of the soil and the monopile is affected by the design parameters of the foundation. The initial conditions of the system yield transient dynamic phenomena. A braking wave at t = 0 causes different dynamic response than the steady-state conditions due to a harmonic wave load. In the present work, an integrated analytical model simulating the above dynamic phenomena is proposed. With the aid of double integral transforms and generalized function properties, a solution of the corresponding differential equations for the monopile-soil-foundation system and the boundary and initial conditions is derived. A parametric study is carried out, and results of the effect of the design parameters and soil properties are presented and discussed.

Reliability Index of Wind-Solar Hybrid Power Plants using the Expected Energy Not Supplied Method

2019 ◽  
Vol 8 (4) ◽  
pp. 9449-9456
Keyword(s):  
Power Plant ◽  
Power Systems ◽  
Electricity Market ◽  
Reliability Index ◽  
Power Plants ◽  
Initial Conditions ◽  
Hybrid Plant ◽  
Total Power ◽  
Hybrid Power ◽  
Hybrid Power Plant

This paper proposes the reliability index of wind-solar hybrid power plants using the expected energy not supplied method. The location of this research is wind-solar hybrid power plants Pantai Baru, Bantul, Special Region of Yogyakarta, Indonesia. The method to determine the reliability of the power plant is the expected energy not supplied (EENS) method. This analysis used hybrid plant operational data in 2018. The results of the analysis have been done on the Pantai Baru hybrid power plant about reliability for electric power systems with EENS. The results of this study can be concluded that based on the load duration curve, loads have a load more than the operating kW of the system that is 99 kW. In contrast, the total power contained in the Pantai Baru hybrid power plant is 90 kW. This fact makes the system forced to release the load. The reliability index of the power system in the initial conditions, it produces an EENS value in 2018, resulting in a total value of 2,512% or 449 kW. The EENS value still does not meet the standards set by the National Electricity Market (NEM), which is <0.002% per year. Based on this data, it can be said that the reliability of the New Coast hybrid power generation system in 2018 is in the unreliable category.

A Simplified Design Model for Modular Steel Buildings Subject to Vapor Cloud Explosions (VCEs)

2020 ◽  
Vol 14 ◽  
Author(s):  
Osama Bedair
Keyword(s):  
Dynamic Response ◽  
Minimum Cost ◽  
Design Parameters ◽  
Front Wall ◽  
Steel Buildings ◽  
Element Analysis ◽  
Analysis And Design ◽  
Vapor Cloud ◽  
Building Components ◽  
Analytical Expressions

Background: Modular steel buildings (MSB) are extensively used in petrochemical plants and refineries. Limited guidelines are available in the industry for analysis and design of (MSB) subject to accidental vapor cloud explosions (VCEs). Objectives: The paper presents simplified engineering model for modular steel buildings (MSB) subject to accidental vapor cloud explosions (VCEs) that are extensively used in petrochemical plants and refineries. Method: A Single degree of freedom (SDOF) dynamic model is utilized to simulate the dynamic response of primary building components. Analytical expressions are then provided to compute the dynamic load factors (DLF) for critical building elements. Recommended foundation systems are also proposed to install the modular building with minimum cost. Results: Numerical results are presented to illustrate the dynamic response of (MSB) subject to blast loading. It is shown that (DLF)=1.6 is attained at (td/t)=0.4 for front wall (W1) with (td/T)=1.25. For side walls (DLF)=1.41 and is attained at (td/t)=0.6. Conclusions: The paper presented simplified tools for analysis and design of (MSB) subject accidental vapor cloud blast explosions (VCEs). The analytical expressions can be utilized by practitioners to compute the (MSB) response and identify the design parameters. They are simple to use compared to Finite Element Analysis.

scholarly journals Perancangan Pembangkit Listrik Tenaga Angin Dengan Turbin Ventilator Sebagai Penggerak Generator

2017 ◽  
Vol 18 (2) ◽  
pp. 68
Author(s):  
Made Padmika ◽  
I Made Satriya Wibawa ◽  
Ni Luh Putu Trisnawati
Keyword(s):  
Wind Speed ◽  
Power Plant ◽  
Wind Power ◽  
Wind Power Plant ◽  
Maximum Output ◽  
Dc Voltage ◽  
Input And Output ◽  
Instrument Testing

A prototype of a wind power plant had been created using a ventilator  as a generator spiner. This power plant utilizes wind speed as its propulsion. Electricity generated in the DC voltage form between 0 volts up to 7.46 volts. The MT3608 module is used to stabilize and raise the voltage installed in the input and output of the charging circuit. For instrument testing, the wind speed on 0 m/s up to 6 m/s interval used. Maximum output of this tool with a wind speed of 6 m/s is 7.46 volts.

scholarly journals LCA and Exergo-Environmental Evaluation of a Combined Heat and Power Double-Flash Geothermal Power Plant

2021 ◽  
Vol 13 (4) ◽  
pp. 1935
Author(s):  
Vitantonio Colucci ◽  
Giampaolo Manfrida ◽  
Barbara Mendecka ◽  
Lorenzo Talluri ◽  
Claudio Zuffi
Keyword(s):  
Life Cycle ◽  
Power Plant ◽  
Environmental Analysis ◽  
Combined Heat And Power ◽  
Hot Water ◽  
Environmental Cost ◽  
Published Data ◽  
Geothermal Power Plant ◽  
Geothermal Power ◽  
Double Flash

This study deals with the life cycle assessment (LCA) and an exergo-environmental analysis (EEvA) of the geothermal Power Plant of Hellisheiði (Iceland), a combined heat and power double flash plant, with an installed power of 303.3 MW for electricity and 133 MW for hot water. LCA approach is used to evaluate and analyse the environmental performance at the power plant global level. A more in-depth study is developed, at the power plant components level, through EEvA. The analysis employs existing published data with a realignment of the inventory to the latest data resource and compares the life cycle impacts of three methods (ILCD 2011 Midpoint, ReCiPe 2016 Midpoint-Endpoint, and CML-IA Baseline) for two different scenarios. In scenario 1, any emission abatement system is considered. In scenario 2, re-injection of CO2 and H2S is accounted for. The analysis identifies some major hot spots for the environmental power plant impacts, like acidification, particulate matter formation, ecosystem, and human toxicity, mainly caused by some specific sources. Finally, an exergo-environmental analysis allows indicating the wells as significant contributors of the environmental impact rate associated with the construction, Operation & Maintenance, and end of life stages and the HP condenser as the component with the highest environmental cost rate.

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