scholarly journals A Hybrid Metaheuristic Optimization Approach for the Synthesis of Operating Procedures for Optimal Drum-Boiler Startups

2021 ◽  
Vol 11 (11) ◽  
pp. 5085
Author(s):  
Emilio Garduno ◽  
Erik Rosado-Tamariz ◽  
Miguel A. Zuniga-Garcia ◽  
Rafael Batres

A steam generator serves as a power generation equipment that uses the expansive power of steam to generate electricity. The startup process of a steam generator plays an important process in a power plant to adjust its electricity generation in response to changes in load demand. As renewable generation plants increase, the levels of variability in electricity production increase. Fast startups become instrumental as they enable traditional power generation plants to provide the quantity of electricity missing when variable renewable energies cannot satisfy the load demand. The drum boiler is one of the main pieces of equipment involved in the startup process of a steam generator. However, if the startup process is carried out too fast, excessive thermal stresses may occur, thus provoking damage to the components of the drum boiler. This paper proposes a dynamic optimization methodology to synthesize operating procedures that minimize the startup time of the drum boiler while avoiding the excessive formation of thermal stresses. Since valve operations influence the time-varying behavior of the steam, dynamic simulation is needed in order to evaluate the operating procedure. The proposed algorithm is based on two important elements of two metaheuristic algorithms: the acceptance probability of the simulated annealing algorithm and the tabu search memory structures. A case study evaluates the proposed approach by comparing it against results previously published in the literature.

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3463
Author(s):  
Xueliang Yuan ◽  
Leping Chen ◽  
Xuerou Sheng ◽  
Mengyue Liu ◽  
Yue Xu ◽  
...  

Economic cost is decisive for the development of different power generation. Life cycle cost (LCC) is a useful tool in calculating the cost at all life stages of electricity generation. This study improves the levelized cost of electricity (LCOE) model as the LCC calculation methods from three aspects, including considering the quantification of external cost, expanding the compositions of internal cost, and discounting power generation. The improved LCOE model is applied to three representative kinds of power generation, namely, coal-fired, biomass, and wind power in China, in the base year 2015. The external cost is quantified based on the ReCiPe model and an economic value conversion factor system. Results show that the internal cost of coal-fired, biomass, and wind power are 0.049, 0.098, and 0.081 USD/kWh, separately. With the quantification of external cost, the LCCs of the three are 0.275, 0.249, and 0.081 USD/kWh, respectively. Sensitivity analysis is conducted on the discount rate and five cost factors, namely, the capital cost, raw material cost, operational and maintenance cost (O&M cost), other annual costs, and external costs. The results provide a quantitative reference for decision makings of electricity production and consumption.


Author(s):  
Segen F. Estefen ◽  
Paulo Roberto da Costa ◽  
Eliab Ricarte ◽  
Marcelo M. Pinheiro

Wave energy is a renewable and non-polluting source and its use is being studied in different countries. The paper presents an overview on the harnessing of energy from waves and the activities associated with setting up a plant for extracting energy from waves in Port of Pecem, on the coast of Ceara State, Brazil. The technology employed is based on storing water under pressure in a hyperbaric chamber, from which a controlled jet of water drives a standard turbine. The wave resource at the proposed location is presented in terms of statistics data obtained from previous monitoring. The device components are described and small scale model tested under regular waves representatives of the installation region. Based on the experimental results values of prescribed pressures are identified in order to optimize the power generation.


2014 ◽  
Vol 29 (suppl.) ◽  
pp. 31-38 ◽  
Author(s):  
Markus Esch ◽  
Dietrich Knoche ◽  
Antonio Hurtado

For future high temperature reactor projects, e. g., for electricity production or nuclear process heat applications, the steam generator is a crucial component. A typical design is a helical coil steam generator consisting of several tubes connected in parallel forming cylinders of different diameters. This type of steam generator was a significant component used at the thorium high temperature reactor. In the work presented the temperature profile is being analyzed by the nodal thermal hydraulics code TRACE for the thorium high temperature reactor steam generator. The influence of the nodalization is being investigated within the scope of this study and compared to experimental results from the past. The results of the standard TRACE code are compared to results using a modified Nusselt number for the primary side. The implemented heat transfer correlation was developed within the past German HTR program. This study shows that both TRACE versions are stable and provides a discussion of the nodalization requirements.


2019 ◽  
Vol 12 (5) ◽  
pp. 156-171
Author(s):  
A. V. Zimakov

Clean energy transition is one of major transformation processes in the EU. There are different approaches among EU countries to decarbonization of their energy systems. The article deals with clean energy transition in France with the emphasis on power generation. While this transformation process is in line with similar developments in the EU, the Franch case has its distinct nature due to nuclear power domination in electricity production there. It represents a challenge for the current model as the transition is linked to a sharp drop of nuclear share in the power mix. It is important to understand the trajectory of further clean energy transition in France and its ultimate model. The article reviews the historical roots of the current model (which stems from Messmer plan of the 1970-es) and its development over years, as well as assesses its drawbacks and merits in order to outline possible future prospects. The conclusion is that the desired reduction of nuclear energy is linked not solely to greening process but has a complex of reasons, the ageing of nuclear reactors being one of them. Nuclear power remains an important low-carbon technology allowing France to achieve carbon neutrality by 2050. A desired future energy model in France can be understood based on the analysis of new legislation and government action plans. The targeted model is expected to balance of nuclear and green energy in the generation mix in 50% to 40% proportion by 2035, with the rest left to gas power generation. Being pragmatic, French government aims at partial nuclear reactors shut down provided that this will not lead to the rise of GHG emissions, energy market distortions, or electricity price hikes. The balanced French model is believed to be a softer and socially comfortable option of low-carbon model.


2000 ◽  
Author(s):  
M. Bianchi ◽  
E. Gadda ◽  
A. Peretto

Abstract The European electric market is going to be fully liberalized moving the problems, related to the minimization of the electric energy production cost, to the Independent Power Producers. In the present paper, a computational code, developed by the Authors, to discover the management strategy permitting to minimize the total variable cost (in terms of fuel consumption) required by a power generation system to face a specific load demand, is described. Subsequently, the code has been applied to an existing power generation system comparing the fuel consumption in different management strategies. It has also emerged that the code may represent an useful advice in the power generation system upgrading feasibility, calculating the fuel saving obtainable with the addition of new or repowered units.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Jing-yu Liu ◽  
Jiu-ju Cai

Electric power is an important energy in steel industry. Electricity accounts for roughly 20% to 30% of the gross energy consumption and costs about 10% of the gross cost of energy. In this paper, under the premise of ensuring the stability of energy supply and the normal production safety, the mathematical programming method and the dynamic mathematical optimization model were used to set up the surplus gas in the optimal allocation among the buffer users and steam production dispatching for the production equipment. The application of this optimization model can effectively improve the energy efficiency and the accuracy of power generation, making full use of secondary energy and residual heat. It also can realize the rationalization of the electricity production structure optimization which can effectively reduce the flare of the gas and steam on one hand, and save energy and decrease production cost on the other.


Author(s):  
Adarsh Madhavan ◽  
Brian Lee ◽  
Claudio A. Canizares ◽  
Kankar Bhattacharya

Author(s):  
Nicolas J. Mertens ◽  
Falah Alobaid ◽  
Bernd Epple ◽  
Hyun-Gee Kim

The daily operation of combined-cycle power plants is increasingly characterized by frequent start-up and shutdown procedures. In addition to the basic requirement of high efficiency at design load, plant operators therefore acknowledge the relevance of enhanced flexibility in operation — in particular, fast start-ups — for plant competitiveness under changing market conditions. The load ramps during start-up procedure are typically limited by thermal stresses in the heat recovery steam generator (HRSG) due to thick-walled components in the high pressure circuit. Whereas conventional HRSG design is largely based on simple steady-state models, detailed modelling and dynamic simulation of the relevant systems are necessary in order to optimize HRSG design with respect to fast start-up capability. This study investigates the capability of a comprehensive process simulation model to accurately predict the dynamic response of a triple-pressure heat recovery steam generator with reheater from warm and hot initial conditions to the start-up procedure of a heavy-duty gas turbine. The commercial combined-cycle power plant (350 MWel) was modelled with the thermal-hydraulic code Apros. Development of the plant model is based on geometry data, system descriptions and heat transfer calculations established in the original HRSG design. The numerical model is validated with two independent sets of measurement data recorded at the real power plant, showing good agreement.


Sign in / Sign up

Export Citation Format

Share Document