Modern Power Plants Research Articles

USE OF IIoT TECHNOLOGIES IN ENGINE MONITORING AND CONTROL SYSTEMS

Determining the operating parameters of engine systems is very important to ensure its long-term reliability. Modern power plants use a large number of modern electronic components (sensors, controllers, etc.). All systems generate a huge volume of data that must be tracked, processed and analyzed, which in turn creates calls to gateways and servers. However, the current state of development of microcontrollers and their power allow the use of fog computing, which can lead to more efficient use of both the power plant and data transmission systems. Also, the use of modern microcontrollers and fog computing allows modernizing old power plants with minimal effort and creating new information nodes for monitoring the state of nodes and engine systems and easily combining them with systems already existing on the engine. The selection of a microcontroller and justification of its type for the modernization of the fuel system of a diesel engine are considered. Rapid processes occur in the high-pressure fuel system of diesel engines, which can be determined by changes in fuel pressure. For detailed measurement of processes in the fuel system, measurements should be made with a frequency of at least 24 kHz, i.e.: if the crankshaft rotation frequency is 4000 min-1, then 24,000 measurements should be made every second (when registering data after 1 degree of crankshaft rotation). Another indicator that imposes its requirements is the bit rate of the analog-to-digital converter (ADC), which depends on the range of recorded values. For example, an ADC with a resolution of 8 bits is capable of outputting 256 discrete values (0…255). That is, the higher the bit rate, the more sensitive the converter is to signal changes, and 8 bits may not be enough. Thus, even a small number of sensors can generate a huge amount of data. Transmitting large amounts of data is irrational and can lead to data loss and "clogging" of transmission channels, which challenges the computational performance of the microprocessor.

Unexpected thermal aging effect on brittle fracture and elemental segregation in modern dissimilar metal weld

A full-scale dissimilar metal weld safe-end mock-up, precisely replicating a critical component of a modern nuclear power plant, was investigated. The brittle fracture behavior, carbide evolution and nanoscale elemental segregation in the heat-affected zone (HAZ) of low alloy steel (LAS) were analyzed under both post-weld heat-treated and thermally-aged conditions (400 °C for 15,000 h, equivalent to 90 years of operation) using analytical electron microscopy and atom probe tomography. The observed increase in grain boundary (GB) decohesion and intergranular cracking on the fracture surface and the decrease of fracture toughness are primarily attributed to P and Mn segregation to GBs and the coarsening of carbides upon long-term thermal aging. The direct observations of significant elemental segregation to GBs and the consequent reduction in fracture toughness in the HAZ are unexpected for modern low-phosphorus LASs, highlighting potential concerns for evaluating the structural integrity of modern nuclear power plants.

A hybrid YDSE - THDCNN approach based multi objective optimization of energy management for renewable energy sources with electric vehicles

Thermal power plants have long been essential to the fossil fuel-based electricity supply chain, according to statistics studies. Nevertheless, due to the enormous initial and ongoing expenses of modern power plants as well as their negative environmental effects. This manuscript proposes a hybrid technique for grid-connected load-following hybrid photovoltaic and wind microgrid with a grid-connected electric vehicle charging system. The proposed hybrid technique is the joint execution of both Young's double-slit experiment optimizer (YDSE) and the Tree Hierarchical Deep Convolutional Neural Network (THDCNN). Hence, it is named as YDSE-THDCNN. The major objective of the proposed technique is to reduce the fuel, operation, and maintenance costs, as well as to reduce the environmental costs and maximize the efficiency of the system. The proposed YDSE technique is utilized to generate the control signal of the inverter and the optimal signal will be predicted by the THDCNN. By then, the MATLAB working platform has adopted the proposed way, and the existing method is used to compute its execution. The proposed method outperforms any existing techniques, including the Genetic Algorithm (GA), Butterfly Optimization Algorithm (BOA), and Particle Swarm Optimization (PSO) Algorithm. The existing method shows the cost of 2.6$, 3.8$, 4.6$, and the proposed method shows the cost of 1.3$ which is lower than the other existing method.

Optimizing a hybrid solid oxide fuel cell-gas turbine and geothermal energy system for enhanced efficiency and economic performance in power and hydrogen production scenario

Geothermal energy is utilized due to its sustainability and ability to provide a continuous low-emission source of heat, making it an ideal complement to the high-efficiency requirements of modern power plants. This study investigates a novel configuration coupling a solid oxide fuel cell-gas turbine unit with a dual-flash binary geothermal structure, enhanced by low-temperature electricity generation and hydrogen production subsystems. This configuration incorporates a regenerative steam Rankine cycle and a proton exchange membrane electrolyzer to achieve an efficient overall design. The setup is evaluated from thermodynamic and economic perspectives using a non-dominated sorting genetic algorithm-II for optimization. A complete parametric study assesses the sensitivity of critical variables. Multi-objective optimization is conducted across three scenarios considering exergy efficiency, hydrogen production rate, sum unit cost of products, and the payback period as objective functions. Results indicate an optimal exergy efficiency of 56.95% and a hydrogen production rate of 0.22 kg/h, with a product unit cost of $7.06/GJ and a payback period of 1.12 years. The parametric study underscores the significant impact of the number of solid oxide fuel cells and their existing density on key variables of the presented configuration. This study highlights the system's potential for efficient and economically feasible power and hydrogen production.

Analyzing the Effects of Atmospheric Turbulent Fluctuations on the Wake Structure of Wind Turbines and Their Blade Vibrational Dynamics

In recent trends, a rising demand for renewable energy has driven wind turbines to larger proportions, where lighter blade designs are often adopted to reduce the costs associated with logistics and production. This causes modern utility-scale wind turbine blades to be inherently more flexible, and their amplified aeroelastic sensitivity results in complex multi-physics reactions to variant atmospheric conditions, including dynamic patterns of aerodynamic loading at the rotor and vortex structure evolutions within the wake. In this paper, we analyze the influence of inflow variance for wind turbines with large, flexible rotors through simulations of the National Rotor Testbed (NRT) turbine, located at Sandia National Labs’ Scaled Wind Farm Technology (SWiFT) facility in Lubbock, Texas. The Common Ordinary Differential Equation Framework (CODEF) modeling suite is used to simulate wind turbine aeroelastic oscillatory behavior and wind farm vortex wake interactions for a range of flexible NRT blade variations, operating in differing conditions of variant atmospheric flow. CODEF solutions of turbine operation in Steady-In-The-Average (SITA) wind conditions are compared to SITA wind conditions featuring a controlled gust-like pulse overimposed, to isolate the effects of typical wind fluctuations. Finally, simulations of realistic time-varying wind conditions from SWiFT meteorological tower measurements are compared to the solutions of SITA wind conditions. These increasingly complex atmospheric inflow variations are tested to show the differing effects evoked by various patterns of spatiotemporal atmospheric flow fluctuations. An analysis is presented for solutions of wind turbine aeroelastic response and vortex wake evolution, to elucidate the consequences of variant inflow, which pertain to wind turbine dynamics at an individual and farm-collective scale. The comparisons of simulated farm flow for SITA and measured fluctuating wind conditions show that certain regions of the wake contain up to a 12% difference in normalized axial velocity, due to the introduction of wind fluctuations. The findings of this study prove valuable for practical applications in wind farm control and optimization strategies, with particular significance for modern utility-scale wind power plants operating in variant atmospheric conditions.

Hydrogen vs. methane: A comparative study of modern combined cycle power plants

This article compared modern hydrogen power plants over a wide range of total compression ratios while maintaining constant system output. In addition, the conventional modern new combined cycle power plant fueled by 100 % methane serves as a reference (comparative) variant representing the currently constructed generating units. Simulations were done using Ebsilon Professional software in the total compression ratio range of 20–50. Previous literature has mainly been based on comparing only the efficiency of GRAZ systems with a combined cycle power plant. The paper discusses a number of performance characteristics. Attention was drawn to the limitations of the currently used COT temperature and the temperature of the compressed medium. For the gas-steam power plant, hydrogen was traditionally burned in air, and in the Graz system, hydrogen was burned in pure oxygen. The structures of the analysed systems were presented and characterised, and their main computational assumptions were standardised in order to compare the systems. A common turbine cooling model was used for both systems. The methodologies for evaluating the performance of energy systems were discussed. Efficiencies, and levels of CO2 emissions per unit were compared for the studied systems. The calculations showed that for the currently used combustion outlet temperature (COT) of 1600 °C, the Graz system achived the best results. The system achieved a COT of 1600 °C for a total compression ratio of 82, which is much higher than that of the main analyses. It operated without CO2 emissions and had an efficiency of 56.21 %, considering the energy consumption of the air separation unit (ASU). For the modern new combined cycle power plant fueled by 100 % methane and for a hydrogen-fueled variant systems, the efficiencies were 53.86 % and 51.39 %, respectively. The modern gas-steam power plant had a high emission rate compared to other systems, reaching 325.17 kgCO2/MWh.

Advanced Concept for Participation of Large Wind Farms in Ancillary Services

The use of renewable energies is steadily growing. Wind energy is the main installed type of renewable energy in Germany. Wind power plants are concentrated in large wind farms. These wind farms are connected to high voltage grids. Despite the high level of installed wind power, wind farms have not contributed to voltage and frequency control (primary, secondary and tertiary control) until now. Wind farm owners receive a fixed payment from the transmission system operator for the energy they generate. This payment is much higher than the average variable costs of conventional power plants. This study shows that modern wind power plants and farms can also support voltage and frequency control. Wind farm owners receive more income through participating in frequency control than from the fixed payment for energy generated. This extra income can help to reduce the fixed payment for energy generated by wind farms.

PURE AMMONIA COMBUSTION IN A BIDIRECTIONAL SWIRLING FLOW

The paper reports on the new pure ammonia combustion technology based on a bidirectional swirling flow formation. This technology allows for avoiding the application of such additional efforts as fuel preheating and blending, oxidizer modification, and plasma assistance normally required for ammonia combustion. Experiments showed that pure ammonia combustion in a bidirectional swirling flow is possible at both lean and rich operation modes. The lowest achieved value of the equivalence ratio is 0.503 compared to conventional and swirl combustors where it is equal to 0.8. This became possible due to the toroidal geometry of the bidirectional vortex chamber where convective fuel preheating occurs as a natural process and the flame front surface area is increased. The presented results allow consideration of bidirectional combustors for use in modern power plants where ammonia is applied as a hydrogen-containing fuel.

Techno-economic analysis on the balance of plant (BOP) equipment due to switching fuel from natural gas to hydrogen in gas turbine power plants

<abstract> <p>The concerns over greenhouse gas emissions, environmental impacts, climate change, and sustainability continue to grow. As a result of countermeasures, many modern gas turbine power plants and combined cycle power plants are considering to use hydrogen as a clean fuel alternative to fossil fuels in the power plant industry. We assessed the implications of such transition from natural gas to hydrogen as fuel in a gas turbine power plant's balance of plant (BOP) equipment. Using the DWSIM process simulation software and the methodology of compression power changes against different gas compositions, the impact of blending hydrogen with natural gas on temperature differentials, energy consumption, adiabatic efficiency, compression power, and economic implications in gas turbine power plants were examined in this paper. We discovered, through analysis, that there was not a noticeable boost in compression power or energy consumption when 50% hydrogen and 50% natural gas were blended. Similarly, there was no discernible difference in temperature differentials or adiabatic efficiency when 30% hydrogen and 70% natural gas were blended. Moreover, mixing 50% hydrogen and 50% natural gas did not result in a noticeable cost climb. In addition, the techno-economic analysis presented in this paper offered valuable insights for power plant engineers, power generation companies, investors in energy sectors, and policymakers, highlighting the nature of the fuel shift and its implications on the economy and technology.</p> </abstract>

Analysis of the main approaches, methods of selection and justification of the parameters and modes of wind power plant for integration into the work of the electric power transmission

One of the priority directions for the development of the electric power industry in Ukraine is the development and use of alternative and renewable energy sources, which leads to a reduction in dependence on the import of electricity. A large part of Ukraine's territory is characterized by favorable conditions for generating electricity using modern wind power plants.
 The article discusses the integration of wind power plants without considering other renewable energy sources. Compared to other sources of renewable energy, the operation of wind power plants has a random nature of electricity production, as the generated power can significantly vary during a day. This requires to take into account certain requirements for power systems during the integration and co-operation with wind power plants. Therefore, in the paper, wind power plants are considered separately from other sources of renewable energy, as they have their own peculiarities and can affect the operation of power systems.
 Integration of a significant amount of renewable energy sources, including wind power plants, into power systems requires solving various tasks related to the characteristics and functionality of such plants, as well as the structure of the generating sources of power systems. Among these tasks, it is necessary to ensure the necessary reserve capacity to timely compensate for changes during electricity generation, maintain the reliability of power system operation, and take measures to compensate for possible reduction in the quality of electrical energy. In fact, the processes of changing the power generated by wind power plants occur quite rapidly, especially in case of sudden deterioration of weather conditions, which is a fairly common phenomenon.
 The methods of selection and justification of parameters and operating modes of wind energy installations for integration into electric power systems have been analyzed. Various approaches to the selection of wind energy installations parameters and modes are described in the work, focusing on methods that ensure system reliability or adequacy of generation.
 Methods for selecting and justifying parameters and modes of wind power plants for integration into operation of power systems based on power and energy balance have been formulated. Key indicators that consider electricity demand conformity are defined in the work, along with approaches to balancing energy production and consumption.
 An evaluation of the effectiveness of wind power plants in different integration modes into power systems operation has been performed, taking into account economic aspects. The impact of different modes on the rational use of generated energy, particularly in cases of insufficient and excess generation, is examined, and economic indicators associated with these modes are considered.
 An analysis of the exact match mode (zero imbalance) of wind power plants in the context of integration into operation of PSs has been conducted. The utilization of storage and auxiliary maneuvering capacities' effects on the duration of the exact match mode and the level of zero imbalance are determined.

Emissions of Sulphur Dioxide (SO2) from Coal-Fired Power Plants in Serbia and Bosnia-Herzegovina: First Attempts of a Validation of TROPOMI Satellite Products with Airborne In Situ Measurements

The Western Balkan region is known for emitting alarmingly high sulphur dioxide amounts from coal-fired power plants. Though a number of environmental regulations have been introduced in recent years (e.g. desulphurisation installations, construction of modern power plants), the pollution burden is still much higher than recommended by the authorities. A number of different montoring systems are required to observe the growing pollution situation in the Western Balkan region, partly caused by a high energy demand from outside (e.g. Western Europe).Several of the top ten SO2 polluters in Europe are located in Bosnia-Herzegovina and Serbia. Here we present the first in situ measurements of sulphur dioxide in this region conducted with a German research aircraft in cooperation with local scientists in Bosnia-Herzegovina and Serbia. Two of the strongtest emitting coalfired power plants were selected for the measurements in autumn 2020: Tuzla in Bosnia-Herzegovina and Nikola Tesla in Serbia (Nikola Tesla). The measurements were mainly conducted in the boundary layer (below ~1 km altitude in winter). Downwind of the power plants, extremely high SO2 mixing ratios exceeding 100 parts per billion (ppb = nmol mol-1 ) were measured at a distance of ~20-40 km from the sources. The SO2 plumes from the power plants were trapped in well-defined inversion layers between ~500-1000 m altitude. The airborne measurements can be used to validate synchronous spaceborne SO2 measurements from the TROPOspheric Monitoring Instrument (TROPOMI) onboard the Sentinel-5P satellite. A first intercomparison indicates some problems with dense smoke clouds frequently covering these countries in the winter months. However, it turned out that the Nikola Tesla flight is to some extent suited for a TROPOMI-SO2 validation, since it was obtained during cloud-free conditions with a well-defined vertical extension of the probed SO2 plume (needed to estimate the Vertical Column Density, VCD, measured by the satellite). In addition, these airborne measurements accompanied by model simulations can be used to determine the SO2 emission strength of the power plants and to compare it to the source strength reported by the power plant operators. The results indicate a reasonable agreement between the airborne measurements, model results, emission inventories, and satellite measurements for the Nikola Tesla power plants.

АНАЛІЗ ПЕРСПЕКТИВ РОЗВИТКУ ТЕЦ УКРАЇНИ В УМОВАХ ІНТЕГРАЦІЇ В ЗАГАЛЬНОЄВРОПЕЙСЬКИЙ ПРОСТІР

Modern heat and power plants (HPPs) face numerous challenges related to energy efficiency, the integration of renew-able energy sources, and environmental sustainability. The article examines the possibilities and prospects for the de-velopment of HPPs taking into account current trends and challenges. The main directions of HPP development include the integration of renewable energy sources (RES), the decentraliza-tion of energy systems, a focus on environmental sustainability, and the development of legislative and regulatory frameworks. These measures will contribute to the sustainable development of the energy infrastructure, ensuring en-ergy security, and improving environmental quality. Bibl.7, fig. 4, table. Keywords: heat and power plant, energy efficiency, renewable energy sources, environmental sustainability, decentrali-zation of energy systems, energy security, sustainable development.

Quantification of cogeneration vulnerability towards the climate change: framework development

Cogeneration is a vigorous measure to both decrease greenhouse gases emissions and improve an overall efficiency of the primary energy use. The climate change poses serious risks on operation of combined heat and power (CHP) plants due to the shifts in heating load patterns. This work investigates linking of the heating demand to the climate conditions and introduces a framework which can be used to develop an adaptation strategy for district heating systems. We demonstrate viability of the proposed approach by a case study assessing sensitivity of the CHP efficiency to the climate warming across China considering a modern combined-cycle gas-fired power plant with steam extraction. Outputs of the case study have demonstrated that CHP plants are generally more vulnerable towards the climate change in world regions with harsher climate conditions. An effective measure to increase resilience of the cogeneration sector is to account for anticipated climate change effects by applying adjustments to the reference climate inputs used when designing CHP plants.

Employment of Intelligent Predictive Maintenance on Thermal Power Plant Component Parts Taking Condenser Vacuum as a Case Study

This work proposes deployment of machine learning in the maintenance of individual constituent parts of steam power plant assemblages. With the condenser vacuum of a steam turbine (in a six-turbine plant assemblage) taken as a case study, information on the past operating parameters of the selected plant component was used to forecast its future working condition. Based on Exponential Gaussian Process of Regression, a model was developed, trained using the diachronic operational data, and employed in determining the future. A quantitative evaluation was employed to provide the distribution of the test values of the data about the lines of regression, as well as to measure the prediction accuracy of the model. The results show MAE and RMSE values are 6.1602 and 7.9286 respectively during the training; while for the prediction, the values are 92.6544 and 92.7235 respectively. It is concluded that modern power plants with myriads of instrumentation and data acquisition mechanisms can leverage on the approach of this study to model and plan the maintenance scheme that best suits and fits individual component units of power plants, since understanding of the anticipatory values of operational parameters helps to determine the likelihood of components failures.

Assessing radioactivity and hazards: analysis of soil, water, and coal samples near a coal-fired thermal power plant and their implications for human health and the environment

ABSTRACT The combustion of coal poses significant risks, increasing the radioactive burden on the atmosphere and affecting the health of individuals near coal mines and coal-fired thermal power plants (CFTPPs). A detailed study was conducted within a 3 km radius surrounding the site of Barapukuria Coal Mine Company Limited (BCMCL), Bangladesh’s premier operational coal-fired thermal power plant, during which 50 soil samples, 50 water samples, and 21 coal samples were collected from a variety of locations inside and beyond the BCMCL boundaries, and these samples were then analysed for radioactivity using a high-purity germanium detector. The range of activity concentrations of 226Ra, 232Th, and 40K in the studied soil, water and coal samples were 24–47, 30–76, and 340–570 Bqkg−1; 1.6–2.9, 1.1–3.8, and 53–92 Bqkg−1; 19–57, 20–97, and 78–170 Bqkg−1 respectively. The majority of hazard indices, including absorbed dose rate, gamma index, effective dose, and excess lifetime cancer risk, associated with soil samples were higher than the world average. This indicates that long-term exposure to terrestrial ionising radiation is unsafe for coal miners and the local community. The quantitative measurements of this study have important implications for planning larger and more modern coal-fired power plants. Additionally, the study’s results underscore the need for municipal officials to impose restrictions and closely monitor the release of fly ash in the vicinity of coal-fired power plants. Furthermore, there is a crucial need to monitor the health of workers and locals living near the power plant to safeguard against potential health risks.

Influence of the Composition and Particle Sizes of the Fuel Mixture of Coal and Biomass on the Ignition and Combustion Characteristics

The work determines the characteristics of the processes of thermal decomposition and combustion when heating coal, cedar needles, and their mixtures with different fuel particle sizes. Based on the results of thermal analysis, the following characteristics were determined: the temperature at which the coke residue ignition occurs, the temperature at which the combustion process is completed, and the combustion index. An analysis was carried out of the interaction between the fuel mixture components on the characteristics of their combustion for compositions (50% coal and 50% biomass) with a particle size of 100–200 μm and 300–400 μm. The combustion kinetic parameters of individual solid fuels and their mixtures containing 50% coal and 50% biomass are compared. The activation energy for coal combustion was 60.3 kJ mol−1, for biomass 24.6 kJ mol−1, and for mixture 42.5 kJ mol−1. The co-combustion of coal and biomass has a positive effect on the main combustion characteristics of solid fuels. Fuels with particle sizes of 100–200, 200–300, and 300–400 μm were studied at temperatures of 500–800 °C under heating conditions in a heated airflow. Using a hardware-software complex for high-speed video recording of fast processes, the ignition delay times were determined, the values of which for the considered fuels vary in the range from 0.01 to 0.20 s. Adding 50 wt% biomass with particle sizes of 100–200, 200–300, and 300–400 μm to coal reduces the ignition delay times of mixtures by 55, 41, and 27%, respectively. The results obtained can become the basis for the conversion and design of modern power plants operating on solid fuel mixtures to co-combust coal with biomass.

Review of Methods for Evaluating the Energy Efficiency of Vehicles with Conventional and Alternative Power Plants

The evaluation of the energy efficiency of vehicles in operating conditions is used to solve management and control tasks in intelligent transport systems. The modern world fleet is characterized by an increase in the share of vehicles with alternative power plants (hybrid, electric, and hydrogen fuel cells). At the same time, vehicles with conventional power plants (internal combustion engines) remain in operation. A wide range of modern power plants determines the relevance of studying the advantages and limitations of existing methods of evaluating the vehicle energy efficiency, delineating the application scope and highlighting promising directions for their further development. The article systematizes the methods of evaluation and management of the energy efficiency of vehicles with conventional and alternative power plants. Special attention is paid to the assessment of energy consumption per unit of transport work at the stage of vehicle operation, taking into account various operational factors. The concept of a 3D morphological model of the transport system for evaluating the energy efficiency of vehicles is presented. An algorithm for the optimization of the current transport system configuration according to the criterion of an increase in the energy efficiency indicator is given.

Enabling control co-design of the next generation of wind power plants

Abstract. Layout design and wake steering through wind plant control are important and complex components in the design and operation of modern wind power plants. They are currently optimized separately, but with more and more computational and experimental studies demonstrating the gains possible through wake steering, there is a growing need from industry and regulating bodies to combine the layout and control optimization in a co-design process. However, combining these two optimization problems is currently infeasible due to the excessive number of design variables and large solution space. In this article, we present a method that enables the coupled optimization of wind power plant layout and wake steering with no additional computational expense than a traditional layout optimization. We developed a geometric relationship between wind turbines to find an approximate optimal yaw angle, bypassing the need for either a nested or coupled wind plant control optimization. It also provides a significant and immediate improvement to wind power plant design by enabling the co-design of turbine layout and yaw control for wake steering. A small co-designed plant shown in this article produces 0.8 % more energy than its sequentially designed counterpart. This additional energy production comes with no additional infrastructure, turbine hardware, or control software; it is simply the outcome of optimizing the turbine layout and yaw control together, resulting in millions of dollars of additional revenue for the wind power plants of the future.

Використання термоакустичних технологій в суднових гібридних енергетичних установках з паливними комірками

Recently, hybrid power plants have gained significant popularity in marine energy systems. These power plants, in addition to traditional thermal engines, include electrochemical power generation systems based on fuel cells. Hybrid marine power plants represent a relatively new technical solution for the maritime fleet, driven by strict environmental emission regulations imposed by international organizations. These regulations primarily target greenhouse gas (GHG) emissions, such as carbon oxides, methane, nitrogen oxides, and other compounds. An analysis of the current state of marine energy and its development trends concludes that the problem lies in the working processes of thermal engines, which are based on fuel combustion. Achieving ecological cleanliness in maritime transport is possible by transitioning to new principles of mechanical energy production that do not rely on chemical fuel combustion. Fuel cells, which generate electricity through electrochemical processes, have the potential to solve this problem. However, the implementation of such electrochemical generators requires a systematic approach to the development of schematic solutions capable of achieving a synergistic effect. The subject of the research is the regularities and parameters of energy exchange processes in hybrid power plants. This study focuses on hybrid power plants with electrochemical generators based on proton exchange membrane fuel cells (PEM FC). The effective operation of hybrid power plants involves the utilization of waste heat from ship equipment. PEM FC is the most widely used type of fuel cell in energy and transportation sectors. The operating temperatures of PEM FCs, depending on their type, range from 60 to 80°C or 120 to 200°C, which poses a challenge for the development of efficient waste heat utilization systems. The aim of the research is to develop waste heat utilization schemes for hybrid power plants with PEM FCs using thermoacoustic heat engines. The study establishes that electrochemical generators can be integrated into the thermal system of modern power plants, and the application of thermoacoustic heat engines expands the potential of waste heat utilization systems. Low-temperature thermoacoustic engines have the capability to convert waste heat generated by PEM FC systems into mechanical work, thereby increasing the overall efficiency of hybrid power plants by 8 to 15%.

Machine learning approach to predict the biofuel production via biomass gasification and natural gas integrating to develop a low-carbon and environmental-friendly design: Thermodynamic-conceptual assessment

A hybrid energy cycle (HEC) based on biomass gasification can be suggested as an efficient, modern and low-carbon energy power plant. In the current article, a thermodynamic-conceptual design of a HEC based on biomass and solar energies has been developed in order to generate electric power, heat and hydrogen energy. The planned HEC consists of six main units: two electric energy production units, a heat recovery unit (HRU), a hydrogen energy generation cycle based on water electrolysis, a thermal power generation unit (based on LFR field), and a biofuel production unit (based on biomass gasification process). Conceptual analysis is based on the development of energy, exergy and exergoeconomic assessments. Besides that, the reduction rate of pollutant emission through the planned HEC compared to conventional power plants is presented. In the planned HEC, when hydrogen energy is not needed, excess hydrogen is feed into the combustion chamber to improve system performance and reduce the need for natural gas. Accordingly, the rate of polluting gases emitted from the cycle can be mitigated due to the reduction of fossil fuels consumption. Further, based on the machine learning technique (MLT), the level of biofuel produced from the mentioned process is estimated. In this regard, two algorithms (i.e., Support vector machine and Gaussian process regression) have been employed to develop the prediction model. The findings indicated that the considered HEC can produce about 10.2 MW of electricity, 153 kW of thermal power, and 71.8 kmol/h of hydrogen energy. In both training and testing sets, the Support vector machine model exhibits better behavior compared the two Gaussian process regression model. Based on machine learning technique, with increasing gasification pressure, the level of biofuel obtained from the process does not increase significantly.