scholarly journals THE EFFICIENCY OF COMBINED-CYCLE CHP PLANT WITH VARIABLE ELECTRIC LOADS, TAKING INTO ACCOUNT THE WEAR AND TEAR OF EQUIPMENT

Author(s):  
R. Z. Aminov ◽  
M. V. Garievsky

The economic efficiency of attracting CHPPs to cover the variable zone of daily electrical load schedules was investigated. The estimation of resource and economic performance of combined -cycle HPPs using the example of PGU-450T taking into account equipment wear under different operating conditions in the daily and weekly sections and different composition of the operating equipment has been performed and optimal load regimes have been determined.

2018 ◽  
Vol 3 (7) ◽  
pp. 50
Author(s):  
Anthony Kpegele Le-ol ◽  
Sidum Adumene ◽  
Kenneth Israel

This work presents a comparative analysis of the thermo-economic performance of a simple, retrofitted and built-in combined cycle power plants within the Delta. The data were obtained from a 25MW gas turbine plant-based engine, retrofitted and MATLAB software was used to model the thermodynamic performance of the plants. The economic prediction of the plants was done using a developed net present value(NPV), internal rate of return (IRR), cost of investment (COR) and payback period (PBP).  The economic concept for plants performance was analysed under uncertainty constraints of energy need, operating conditions, energy cost and energy supply variability. Three plants configuration; simple gas turbine (SGT), retrofitted combined cycle (RCC) and Built-in combined cycle (BCC) was analysed based on these economic performance indicators. The three configurations show a positive NPV, PBP and IRR, with the BCC showing the optimum return on investment. Although the RCC show minimum initial cost on investment compare to BCC, the BCC demonstrates greater overall return with an NPV of $30,755,454.18, IRR of 17.1% and PBP of 6.3years for the period of 20years. The analysis shows cash flow of 34.1% and 52.6% for the RCC and BCC respectively. The result also showed that the plant performs better at a lower ambient temperature and higher relative humidity with a higher return on investment. This research provides great insight into the thermo-economic analysis, and benefits of combined cycle power plant and will aid energy system investors on the choice of the power plant for power generation in the Niger Delta.


Author(s):  
Nicola Palestra ◽  
Giovanna Barigozzi ◽  
Antonio Perdichizzi

The paper presents the results of an investigation on inlet air cooling systems based on cool thermal storage, applied to combined cycle power plants. Such systems provide a significant increase of electric energy production in the peak hours; the charge of the cool thermal storage is performed instead during the night time. The inlet air cooling system also allows the plant to reduce power output dependence on ambient conditions. A 127MW combined cycle power plant operating in the Italian scenario is the object of this investigation. Two different technologies for cool thermal storage have been considered: ice harvester and stratified chilled water. To evaluate the performance of the combined cycle under different operating conditions, inlet cooling systems have been simulated with an in-house developed computational code. An economical analysis has been then performed. Different plant location sites have been considered, with the purpose to weigh up the influence of climatic conditions. Finally, a parametric analysis has been carried out in order to investigate how a variation of the thermal storage size affects the combined cycle performances and the investment profitability. It was found that both cool thermal storage technologies considered perform similarly in terms of gross extra production of energy. Despite this, the ice harvester shows higher parasitic load due to chillers consumptions. Warmer climates of the plant site resulted in a greater increase in the amount of operational hours than power output augmentation; investment profitability is different as well. Results of parametric analysis showed how important the size of inlet cooling storage may be for economical results.


Author(s):  
Charles Forsberg

A combined-cycle power plant is proposed that uses heat from a high-temperature nuclear reactor and hydrogen produced by the high-temperature reactor to meet base-load and peak-load electrical demands. For base-load electricity production, air is compressed; flows through a heat exchanger, where it is heated to between 700 and 900°C; and exits through a high-temperature gas turbine to produce electricity. The heat, via an intermediate heat-transport loop, is provided by a high-temperature reactor. The hot exhaust from the Brayton-cycle turbine is then fed to a heat recovery steam generator that provides steam to a steam turbine for added electrical power production. To meet peak electricity demand, after nuclear heating of the compressed air, hydrogen is injected into the combustion chamber, combusts, and heats the air to 1300°C—the operating conditions for a standard natural-gas-fired combined-cycle plant. This process increases the plant efficiency and power output. Hydrogen is produced at night by electrolysis or other methods using energy from the nuclear reactor and is stored until needed. Therefore, the electricity output to the electric grid can vary from zero (i.e., when hydrogen is being produced) to the maximum peak power while the nuclear reactor operates at constant load. Because nuclear heat raises air temperatures above the auto-ignition temperatures of the hydrogen and powers the air compressor, the power output can be varied rapidly (compared with the capabilities of fossil-fired turbines) to meet spinning reserve requirements and stabilize the grid.


2010 ◽  
Vol 44-47 ◽  
pp. 1240-1245 ◽  
Author(s):  
Hong Zeng ◽  
Xiao Ling Zhao ◽  
Jun Dong Zhang

For combined-cycle power plant performance analysis, a ship power plant mathematical model is developed, including diesel engine, controllable pitch propeller, exhaust gas boiler, turbine generator and shaft generator models. The simulation performance characteristic curves of diesel engine under various loads are given. Comparison of simulation results and experimental data shows the model can well predict the performance of diesel engine in various operating conditions. The specific fuel oil consumption contours of combined-cycle power plant and the relations between engine operating conditions and steam cycle parameters are given. The influence of diesel engine operating conditions to the overall performance of combined-cycle power plant is discussed.


2021 ◽  
Vol 2130 (1) ◽  
pp. 012003
Author(s):  
P Lonkwic ◽  
T Krakowski ◽  
H Ruta

Abstract The systems that monitor individual components of machines and devices are under constant development. The ability to detect damages at an early stage allows failures to be prevented, so any uncontrolled downtime can be predicted in a controlled manner. Continuous monitoring of technical condition is an activity that also helps to reduce the losses due to equipment failures. However, not all areas can be monitored continuously. Such areas include lift guides where wear and tear can occur naturally, i.e. through abrasion of the material layer due to interaction with moving guide shoes or after emergency braking. Emergency braking causes local damages to the guide through plastic deformation of its surface resulting from indentation of the knurled roller of the brake. Such places are cleaned mechanically, which results in local reduction of the cross-sectional area. In such a case, it is difficult to continuously assess the technical condition of guides due to the prevailing operating conditions. Therefore, a concept of a head enabling assessment of the technical condition of guides at every stage of their operation has been developed. This article presents the novel concept of a magnetic head used for assessing the technical condition of lift guide rails that are the running track of lifting equipment. The initial tests were performed on the original test setup. The concept of the developed measuring head was verified for correct operation on specially prepared flat bars with holes. The results obtained in the form of laboratory tests proved that the proposed measuring head concept can be applied to the measurements under real conditions.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Gabriel Valencia-Ortega ◽  
Sergio Levario-Medina ◽  
Marco Antonio Barranco-Jiménez

Abstract The proposal of models that account for the irreversibilities within the core engine has been the topic of interest to quantify the useful energy available during its conversion. In this work, we analyze the energetic optimization and stability (local and global) of three power plants, nuclear, combined-cycle, and simple-cycle ones, by means of the Curzon–Ahlborn heat engine model which considers a linear heat transfer law. The internal irreversibilities of the working fluid measured through the r-parameter are associated with the so-called “uncompensated Clausius heat.” In addition, the generalization of the ecological function is used to find operating conditions in three different zones, which allows to carry out a numerical analysis focused on the stability of power plants in each operation zone. We noted that not all power plants reveal stability in all the operation zones when irreversibilities are considered through the r-parameter on real-world power plants. However, an improved stability is shown in the zone limited by the maximum power output and maximum efficiency regimes.


Author(s):  
V.E. Yurin ◽  
◽  
A.N. Egorov ◽  
D.O. Bashlykov ◽  
A.B. Moskalenko ◽  
...  

With an increase in the share of NPPs in the energy system, it becomes necessary for them to participate in the regulation of the electric load schedule. At the same time, the operation of the NPP with the maximum utilization factor of the installed capacity of the reactor was economically and technically justified. One of the promising ways to solve this problem is to install consumers-regulators at NPPs. The hydrogen energy complex can be effectively used as a consumer-regulator. The authors have previously developed an autonomous hydrogen energy generating complex, scientifically substantiated its economic efficiency. As the study has shown, the economic efficiency of an autonomous hydrogen energy complex directly depends on the sale tariffs for electricity. The low cost of electricity sold leads to a deterioration in economic indicators, up to a lack of recoupment. In this regard, as an alternative option, this work considers the possibility of selling hydrogen and oxygen as a commercial product at existing prices. A comparative study for a range of electricity tariffs and prices for hydrogen and oxygen was carried out on the basis of the methodology presented earlier by the authors, which makes it possible to study ways to improve NPPs on the basis of a comprehensive analysis of economic efficiency, safety and system effects achieved during the installation of new and modernization of existed equipment. The results obtained make it possible to choose the type of hydrogen energy complex depending on the operating conditions for the selected region of operation.


Author(s):  
M. W. Horner ◽  
G. A. Cincotta ◽  
A. Caruvana

This paper presents the results of three significant tests recently performed by GE under the DOE High Temperature Turbine Technology Phase II Program contract. The first test involved a simulated Integrated Gasification Combined Cycle (IGCC) test of a water-cooled composite nozzle exposed to low Btu coal gas at design operating conditions (2600 F + firing temperature, 12 atm pressure). The second test is that of a water-cooled monolithic nozzle, a full-scale model of the second-stage nozzle planned for the Technology Readiness Vehicle Verification Test. The third test demonstrates coolant water delivery, transfer, and metering distribution, from the stationary feed line to the turbine rotor, enroute to individual bucket airfoil coolant passages. These tests successfully demonstrated the IGCC operation with very good results, and show every indication that operation at firing temperatures up to 3000 F is well within the design capability of the water-cooled turbine.


Author(s):  
Vittorio Verda ◽  
Luis Serra ◽  
Antonio Valero

This paper presents a summary of our most recent advances in Thermoeconomic Diagnosis, developed during the last three years [1–3], and how they can be integrated in a zooming strategy oriented towards the operational diagnosis of complex systems. In fact, this paper can be considered a continuation of the work presented at the International Conference ECOS’99 [4–6] in which the concepts of malfunction (intrinsic and induced) and dysfunction [7] were analyzed in detail. These concepts greatly facilitate and simplify the analysis, the understanding and the quantification of how the presence of an anomaly, or malfunction, affects the behavior of the other plant devices and of the whole system. However, what remains unresolved is the so-called inverse problem of diagnosing [3], i.e. given two states of the plant (actual and reference operating conditions), find the causes of deviation of the actual conditions with respect to the reference conditions. The present paper tackles this problem and describes significant advances in addressing how to locate the actual causes of malfunctions, based on the application of procedures for filtering induced effects that hide the real causes of degradation. In this paper a progressive zooming thermoeconomic diagnosis procedure, which allows one to concentrate the analysis in an ever more specific zone is described and applied to a combined cycle. In an accompanying paper (part 2 [8]) the accuracy of the diagnosis results is discussed, depending on choice of the thermoeconomic model.


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