Power Generation Device Research Articles

Design of Nano‐Composite Structured Electrode for High‐Performance and Stability of Metal‐Supported Solid Oxide Cells

AbstractSolid oxide cells are reversible energy‐conversion devices for electric power generation and fuel production with high efficiency. However, robust cell structures and multifunctional electrodes must be provided to achieve high cell performance under multifuel conditions. Herein, a precisely controlled metal‐supported structure and dual‐nanocomposite catalyst is presented. The thermal and shrinkage behaviors of the metal supports play a crucial role in determining the interconnectivity between cell components. Compared to micron‐sized cermets, the dual‐nanocomposite electrode with tremendous three‐phase boundaries drastically improves cell performance by increasing the electrochemical activity for diverse fuel reactions. The developed cells exhibited outstanding maximum power densities of 1.1 and 1.0 W cm−2 in fuel‐cell mode using H2 and CO fuels, and current densities of −0.61 and −0.5 A cm−2 in electrolysis‐cell mode (1.3 V) under H2O/H2 and CO2/CO conditions at 650 °C. These findings suggest fundamental techniques for improving the structural stability and activity of cell components to operate in diverse fuel systems.

Effects of Installing Different Types of Cooling Fins on the Cold Side of a Thermoelectric Power Generation Device on the Thermal Efficiency and Exergy Efficiency of Power Cable Surface Waste Heat Recovery.

This study investigates the thermal efficiency and exergy efficiency of a thermoelectric power generation device for recovering power cable surface waste heat. Numerical simulations are conducted to analyze the impact of different types of cooling fins on the system's performance. The results demonstrate that the installation of cooling fins improves heat transfer efficiency and enhances the thermoelectric power generation device's output power. Among the various fin designs, the system equipped with cooling fins with 17 teeth exhibits the highest performance. These findings highlight the importance of fin design in optimizing the system's thermal efficiency and exergy efficiency. This study provides valuable insights for the development and improvement of thermoelectric power generation systems for power cable surface waste heat recovery applications.

Study on hydrodynamic characteristics of a hybrid wind-wave energy system combing a composite bucket foundation and wave energy converter

In this paper, a new type of combined wind-wave system is proposed, that is, composite bucket foundation-oscillating buoy (CBF-OB) combined device. A three-dimensional numerical wave flume is established by using the renormalization group k–ε model. The hydrodynamic characteristics around the wave and the combined power generation device are studied. The relationship between wave parameters and wave run-up and wave pressure is analyzed. The absorption efficiency performance of the combined power generation device is evaluated. The results show that in the combined power generation system, the wave run-up and wave pressure at 0°–135° around the CBF are smaller than those in the presence of only CBF, but near 180° the ones are larger than those in the presence of only CBF. In the rear side of the combined power generation system, the smaller the scattering parameters, the more obvious the phenomenon of the second wave peak, and the stronger the nonlinearity of the wave and CBF-OB combined power generation system. The proposed CBF-OB combined power generation device can significantly improve the absorption efficiency of the buoy, which can be increased by about 1.5–4.0 times compared with the absorption efficiency under the action of only the buoy alone. There is an optimal power takeoff parameter, that is, when the damping parameter is 500 N·s/m, to maximize the absorption efficiency of the combined power generation device.

Gibbs Adsorption and Zener Pinning Enable Mechanically Robust High-Performance Bi2 Te3 -Based Thermoelectric Devices.

Bi2 Te3 -based alloys have great market demand in miniaturized thermoelectric (TE) devices for solid-state refrigeration and power generation. However, their poor mechanical properties increase the fabrication cost and decrease the service durability. Here, this work reports on strengthened mechanical robustness in Bi2 Te3 -based alloys due to thermodynamic Gibbs adsorption and kinetic Zener pinning at grain boundaries enabled by MgB2 decomposition. These effects result in much-refined grain size and twofold enhancement of the compressive strength and Vickers hardness in (Bi0.5 Sb1.5 Te3 )0.97 (MgB2 )0.03 compared with that of traditional powder-metallurgy-derived Bi0.5 Sb1.5 Te3 . High mechanical properties enable excellent cutting machinability in the MgB2 -added samples, showing no missing corners or cracks. Moreover, adding MgB2 facilitates the simultaneous optimization of electron and phonon transport for enhancing the TE figure of merit (ZT). By further optimizing the Bi/Sb ratio, the sample (Bi0.4 Sb1.6 Te3 )0.97 (MgB2 )0.03 shows a maximum ZT of ≈1.3 at 350 K and an average ZT of 1.1 within 300-473 K. As a consequence, robust TE devices with an energy conversion efficiency of 4.2% at a temperature difference of 215 K are fabricated. This work paves a new way for enhancing the machinability and durability of TE materials, which is especially promising for miniature devices.

Mg Compensating Design in the Melting-Sintering Method For High-Performance Mg3 (Bi, Sb)2 Thermoelectric Devices.

N-type Mg3 (Bi, Sb)2 -based thermoelectric (TE) alloys show great promise for solid-state power generation and refrigeration, owing to their excellent figure-of-merit (ZT) and using cheap Mg. However, their rigorous preparation conditions and poor thermal stability limit their large-scale applications. Here, this workdevelops an Mg compensating strategy to realize n-type Mg3 (Bi, Sb)2 by a facile melting-sintering approach. "2D roadmaps" of TE parameters versus sintering temperature and time are plotted to understand the Mg-vacancy-formation and Mg-diffusion mechanisms. Under this guidance, high weight mobility of 347 cm2 V-1 s-1 and power factor of 34 µWcm-1 K-2 can be obtained for Mg3.05 Bi1.99 Te0.01 , and a peak ZT≈1.55 at 723 K and average ZT≈1.25 within 323-723 K can be obtained for Mg3.05 (Sb0.75 Bi0.25 )1.99 Te0.01 . Moreover, this Mg compensating strategy can also improve the interfacial connecting and thermal stability of corresponding Mg3 (Bi, Sb)2 /Fe TE legs. As a consequence, this workfabricates an 8-pair Mg3 Sb2 -GeTe-based power-generation device reaching an energy conversion efficiency of ≈5.0% at a temperature difference of 439 K, and a one-pair Mg3 Sb2 -Bi2 Te3 -based cooling device reaching -10.7°C at the cold side. This work paves a facile way to obtain Mg3 Sb2 -based TE devices at low cost and also provides a guide to optimize the off-stoichiometric defects in other TE materials.

Examining the feasibility of a bi-evaporator cooling/electricity cycle: A comprehensive analysis of thermodynamic, economic, and environmental aspects, and bi-objective optimization

Although geothermal energy is generally considered benign, it still has its share of problems, including the emission of greenhouse gases that harm the environment. To make informed decisions about geothermal systems, it is imperative to study their environmental impacts. This study uses six approaches to propose and analyze an innovative geothermal-driven bi-evaporator cooling/electricity plan. The proposed efficient design is made of a single-flash cycle and the integration of a modified vapor compression cycle and ejector cooling system assisted by a thermoelectric power generator device. Exergoenvironmental and extended-environmental assessments are performed to examine the environmental impacts of the current devised scheme, including calculating CO2 emissions rate and sustainability index. The suggested plan's performance in the basic design mode using 14 various working fluids showed that R143m had the highest exergetic efficiency, lowest exergoenvironmental index, and lowest cost of production at 35.9%, 0.6002, and 24.67$/GJ, respectively. This working fluid was used for parametric study and bi-objective optimization, which revealed that the vapor generator destroys 157.7 kW of exergy at the optimal point. Additionally, the vapor turbine is the most expensive component at 14.44$/h. Pareto frontier also indicates that the final chosen optimal mode (scenario C) has 27.02% energetic efficiency and 21.33$/GJ production cost, which are higher than the base scenario by 12.55% and 15.66%, respectively. In addition, the optimal scenario reduces the payback period to 8.64 years from 15.68 years in the base scenario.

Research on Multi -mode Power Generation Devices based on Wave Energy

This paper mainly studies a multi-mode power generation device based on wave energy, which is mainly composed of power generation device, energy storage device, monitoring device, through the use of electromagnetic machinery, piezoelectric ceramics, hydraulic system in a variety of ways to generate electricity, and then the energy storage device stable output, is a kind of power generation system will be converted into electrical energy device, to achieve high efficiency conversion of wave energy. Each part of the project is innovative and practical, which has high application value in ocean power generation. Compared with some traditional power generation devices, this device uses a new type of energy, ocean wave energy, which is a pollution-free, clean and renewable new energy. Wave energy has high flow density, huge reserves and wide distribution, which is the main direction of the development of ocean energy utilization in the future. It will make positive contributions to Marine construction, economic development and infrastructure construction of countries and regions along the Belt and Road.

Latent and controllable doping of stimuli-activated molecular dopants for flexible and printable organic thermoelectric generators

Conjugated polymers (CPs) are a promising class of materials for organic thermoelectric generators (OTEGs); however, achieving high electrical conductivity through molecular doping while maintaining compatibility with thin-film printing processes remains a huge challenge. In this paper, we present a novel doping strategy using stimuli-activated molecular dopants (SAMDs) based on photoacid generators (PAGs) that can be activated by light of a specific wavelength. We demonstrate that this approach can effectively control the doping efficiency and optoelectronic properties of CP-PAG-blended thin films, resulting in a wide range of electrical conductivities. Our selected PAG molecules enabled efficient printing of the CP-PAG mixed solution and yielded a high thermoelectric figure of merit. To elucidate the mechanism behind this high thermoelectric performance, we systematically investigated the morphologies, microstructures, and energy structures of the PAG-doped CP thin films and performed various comparative tests. We also demonstrate the feasibility of using SAMDs to print flexible OTEG modules on thin polyimide substrates. We believe that our work represents a significant step toward the development of efficient, scalable, and sustainable thermoelectric devices for power generation and waste heat recovery, and highlights the advantages of PAG-based SAMDs for printable organic thermoelectrics.

High-performance integrated chip-level thermoelectric device for power generation and microflow detection

Miniaturized thermoelectric devices (TED) possess great benefits in energy converting and sensing. By employing improved microfabrication technology, we succeed made an ultra-highly integrated TED with enhanced interfacial and structural qualities at a high filling factor of 61 %. Our micro-TED (2 cm × 2 cm×6 µm, 10,082 TE pairs) achieved an open-circuit voltage up to 2.6 V, an output power of 1.2 mW (temperature difference of 62.8 K). The micro-TED delivered a large temperature gradient up to ∼600 K/mm with input current, achieving a net cooling temperature of 3.6 K with a 3 µm thick thermoelectric layer. As a novel microflow sensor, micro-TED can distinguish ultra-slow cold/hot airflows down to 4 mm/s. The ultra-thin integrated micro-TED can find multi-featured applications in ultra-low-grade thermal energy harvesting, localized chip-to-chip cooling, and hypersensitive sensing.

A fuzzy mathematical model-based approach to customer-side energy management for power companies

Abstract The power industry has a long history of unreasonable structure of electricity consumption, high energy-consuming enterprises, low efficiency of electricity, electric energy in the current is still a bottleneck that restricts economic development. First, a fuzzy mathematical model is established and optimized using adaptive fuzzy control, which can transform the fuzzy information of people’s input language into operation instructions and perform real-time regulation. Then the structure of the power customer side energy management system is designed to control the flexible load of the power customer. Describe the control principles of different devices, and analyze the strategies for start/stop control of power generation devices and charge/discharge control of energy storage devices. This paper combined with the actual situation of the current smart grid construction, researches and elaborates on the methods of power companies to carry out demand management i//n this situation, aiming to provide effective reference for power companies to carry out demand management, so that electricity can better serve the economic development. The research results show that the cost of electricity consumption of the proposed method is only $2.9426, which can effectively improve the economic efficiency of the system and improve the supply and demand balance.

Electroactive Microorganisms in Advanced Energy Technologies.

Large-scale production of green and pollution-free materials is crucial for deploying sustainable clean energy. Currently, the fabrication of traditional energy materials involves complex technological conditions and high costs, which significantly limits their broad application in the industry. Microorganisms involved in energy production have the advantages of inexpensive production and safe process and can minimize the problem of chemical reagents in environmental pollution. This paper reviews the mechanisms of electron transport, redox, metabolism, structure, and composition of electroactive microorganisms in synthesizing energy materials. It then discusses and summarizes the applications of microbial energy materials in electrocatalytic systems, sensors, and power generation devices. Lastly, the research progress and existing challenges for electroactive microorganisms in the energy and environment sectors described herein provide a theoretical basis for exploring the future application of electroactive microorganisms in energy materials.

Towards the Development of Miniature Scale Liquid Fuel Combustors for Power Generation Application—A Review

As the demand for powerful, light energy sources continues to grow, traditional electrochemical batteries are no longer sufficient and combustion-based power generation devices have become an attractive alternative due to their high energy density, compact size, fast recharging time and long service life. While most research on miniature-scale combustors has focused on gaseous fuels, the use of commonly available liquid fuels has the potential to be highly portable and economical. However, the complexity of droplet atomization, evaporation, mixing and burning in a limited volume and short residence time has presented significant challenges for researchers. This review focuses on various methodologies proposed by researchers (like flow burring injector, fuel film injection, injecting into porous media, electrospray and some self-aspirating designs) to overcome these challenges, the combustion behaviour and different instabilities associated with liquid fuels at small scales. The current review intends to present a clear direction to channel the efforts made by researchers to overcome the difficulties associated with liquid fuel combustion at small scales for power generation applications. Additionally, this review aims to give an overview of power systems at the micro and meso scales that operate using liquid fuels. The methodologies introduced like electrospray requires external power, which again makes the system complex. Towards the development of standalone type power generators, the self-aspirating design which makes use of hydrostatic pressure, fuel film injection or taking advantage of exhaust gas enthalpy to preheat and evaporate the liquid fuel are the promising methodologies.

Experimental Study on the Efficiency of Dynamic Marine Thermal Energy Generator Based on Phase Change Compensation

Miniaturized detection devices in the ocean generally experience problems such as short endurance and unreliable power supplies. This article aimed to develop a dynamic ocean temperature difference energy collection device to capture ocean temperature difference energy and provide objective electricity for stable detection devices. The main focus was to conduct experimental research on the effectiveness of a dynamic ocean temperature difference energy power generation device. During the research process, the fact that ammonia gas in a working fluid is easy to liquefy and vaporize was utilized. By utilizing the increase in seawater temperature during the floating process of the device, it vaporized and drove the turbine to rotate for power generation. In the structural design, multiple sets of small air chambers were creatively proposed, which could effectively control the air pressure and improve the stability of the airflow. By charging the airflow to impact the turbine, multiple sets of power generation fans were used to form a stable current. Further, the buoyancy of the device could be changed by adding phase change materials between the air chamber and the device shell, and the temperature difference between the two ends of the phase change materials could be used to change the electron density of the material to form a weak current. In this experimental study, concepts such as the structural design of multiple small gas chambers, miniaturization of energy collection devices, compensation power generation of phase change materials, and application scenarios of devices combined with Argo buoys were all proposed for the first time. The results of this experimental study indicate that the overall power generation of the device is about 2A, and its maximum output power amplitude is about 22 W. The cyclic thermal efficiency of the power generation device can be increased from +0.19% to +0.88%. The development of this thermoelectric power generation device can provide a considerable stable power supply for ocean observation devices, especially the buoy device represented by Argo, which can extend the endurance of deep-sea exploration devices.

The efficient photothermal performance of organic polymeric material poly3-hexylthiophene for solar driven water evaporation and thermoelectric power generation

Photothermal materials for solar evaporators need to have broad light absorption ability and be able to convert into heat efficiently. At present, organic photothermal materials mainly have the problems of narrow absorption spectrum range and low photothermal conversion efficiency. In recent years, the development of photovoltaic materials has attracted the attention of researchers. However, the application of photovoltaic materials to the field of solar driven water evaporation is still rare. Poly(3-hexylthiophene), P3HT, is a typical p-type conjugated polymer that can achieve high power conversion efficiency. P3HT powder has a solar-thermal conversion efficiency of 11.26%. Its absorption range at 300–900 nm provides effective utilization of sunlight and has the potential as an excellent photothermal conversion material. We loaded P3HT into non-woven fabric to obtain an integrated device for simultaneous water evaporation and thermoelectric power generation, with evaporation rate of 1.04 kg m−2 h−1 and output voltage of 58 mV under 1 kW m−2 simulated solar irradiation. This study enriches the application of traditional photovoltaic materials in the field of solar-heat technique and provides guidance in the construction of solar evaporation devices for water-electricity co-generation.

Application of the theory of constraints to unveil the root causes of the limited market penetration of micro gas turbine systems

Micro Gas Turbines are small devices for on-site power and heat generation. Their high maintainability and fuel flexibility make them a suitable technology for transitioning to a greener economy. However, their commercialisation did not match the stakeholders’ expectations. The authors applied the Theory of Constraints – a methodology for the continuous improvement of systems – to the MGT industry introducing a structured and rigorous representation. The constraint – i.e. Root Cause – Analysis identified which entities sustain the cause–effect chain, eventually generating the Undesired Effects. The system constraints link to the specificity and effectiveness of commercialisation strategies and product innovation in agreement with evolutionary market theories. Moreover, the Theory of Constraints emphasises the presence of reinforcement loops that make targeting entities like high product costs ineffective. The missing piece to complete the puzzle is solving a logic block representing the product’s market competitiveness depending on economic and technical factors. This study suggests that combining market-driven innovation and commercialisation is likely the only long-term solution to the lack of commercial success of the technology. However, the work also highlights limitations in the proposed methodology and solutions. To tackle these, the authors suggest and introduce numerical frameworks based on the Theory of Constraint.

Research on Multiple Energy-Saving Strategies for Existing Coach Stations: A Case of the Xi’an Area, China

In the context of China’s dual-carbon goals, energy efficiency in public buildings has become a focal point of public concern. As large-scale public transportation buildings, the indoor thermal comfort and the current state of energy consumption of coach stations are increasingly being emphasized. This research used existing coach stations in the Xi’an region as the object; through on-site investigations and field tests of indoor thermal environments in winter and summer seasons, it was found that the coach stations had energy waste and high energy consumption; the enclosure structures had poor thermal performance; and the stations lacked effective energy-saving measures. Energy-saving transformation strategies were proposed from two aspects: enclosure structures and renewable energy utilization. Using DeST-C for energy consumption, the external walls, roofs, insulation materials, and glass materials were simulated, and nine different combinations of energy-saving schemes were simulated using orthogonal experiments. The optimal scheme was selected based on the comprehensive energy-saving rate and economic analysis results, which included using 80 mm XPS external insulation for the external walls, low-e hollow glass for the windows (low transmittance type), and an 80 mm PUR board for the roof insulation. The energy-saving rate of this scheme was 26.84%. The use of rooftop solar photovoltaic power generation and fresh air heat recovery devices can effectively reduce building energy consumption, and the investment payback period is less than 5 years. The research applications have practical significance for improving the indoor environment of existing coach stations and saving energy consumption.

A novel oxy-enrich near-field thermophotovoltaic system for sustainable fuel: Design guidelines and thermodynamic parametric analysis

Developing new technologies is a key to achieve renewable energy utilization. The near-field thermo-photovoltaics (NFTPV), an emerging power generation device, is investigated from the energy perspective in this paper. A novel oxy-enrich NFTPV system is proposed, and a thermo-physical model is established for sustainable fuel gas based on energy balance. The effects of parameters on system performance are numerically explored, including the furnace size, oxygen ratio, voltage and vacuum gap, etc. Moreover, special attention is paid to the effects of oxygen ratio on system performance under 2 atm of O2/N2 and O2/CO2. Besides, exergy analysis is conducted. The results show that it is more appropriate to control the power density of furnace at 50 kW/m2 in system design. The efficiency of NFTPV system is about twice greater than that of far-field TPV system. The power density of NFTPV system increases by more than 2.5 times when the oxygen ratio increases; the TPV volume can increase by 2–3 times and the efficiency is also improved. The results indicate that oxy-enrich combustion with higher oxygen ratio matches a larger NFTPV system, which reduces the manufacturing difficulty and is significant in engineering. This study provides new ideas and references for NFTPV practical application.

An improvement of stability and dynamic response in hybrid AC-DC microgrids using optimal power control management

Microgrid topologies enable more effective use of renewable resources as well as the autonomous process. Microgrids are effective frameworks for managing dispersed assets such as renewable structures with small-scale distributed generator supplies. Smart grids are adaptable electricity networks that have arisen as a result of the introduction of new technologies and features. It is suggested that a three-terminal AC/DC hybrid microgrid with DC two and AC one terminal be used. A two dual active bridge (DAB) with cascaded H-bridge (CHB) converter with AC grid link-based interactions that connect isolated two DC buses are included in the suggested structure. To minimise the energy generation stages and power devices, the DAB converters are intrinsically linked to the CHB of DC rails based on the structure-specific requirements. To present the unnecessary grid currents and DC rail voltage issues exist by this revised structure topology by simply two power alteration stages, a better solution is suggested that employs zero-sequence voltage (ZSV) injection in the CHB converters. The impacts of managed settings on structure stability and dynamic responsiveness are investigated in order to reduce conflicts among ZSV injection by structure voltage/current regulation. This paper compares the performance of a PI and a PR for DC voltage regulation. A comparison of simulation results for both control approaches is provided. The major difficulty is to normalise the system model in order to identify the appropriate controller settings for robust control. The findings are confirmed and compared to the conventional regulator PI. The suggested 3-Φ AC current and DC rail voltage regulating approach's universal efficacy is proved by MATLAB/Simulink analytical model from the three and five-terminal hybrid AC/DC power structures.

Highly robust and sensitive dual-network freeze-resistant organic hydrogel thermocells

Thermocells (TECs) are eco-friendly and ideal power-generation devices that sustainably convert waste heat into electricity to power wearable electronics. However, their poor mechanical properties, limited operating temperature, and low sensitivity limit their practical application. Hence, K3/4Fe(CN)6 and NaCl thermoelectric materials were introduced into a bacterial cellulose-reinforced polyacrylic acid double-network structure and permeated into a glycerol (Gly)/water binary solvent to prepare an organic thermoelectric hydrogel. The resulting hydrogel had a tensile strength of approximately 0.9 MPa and a stretched length of approximately 410 %; moreover, it worked stably even in the stretched/twisted state. Owing to the introduction of Gly and NaCl, the as-prepared hydrogel exhibited excellent freezing tolerance (− 22 °C). In addition, the TEC also demonstrated excellent sensitivity (~13 s). Good environmental stability and high sensitivity make this hydrogel TEC a promising candidate for thermoelectric power-generation/temperature-monitoring systems.

Research on dynamic temporal and spatial distribution characteristics of electrical power system voltage based on random forest algorithm

AbstractThe theme of this study is to find a method that can more accurately classify the spatiotemporal distribution characteristics of power system voltage dynamics. As more and more new energy power generation devices are added to the power network, the accuracy of traditional methods for classifying the spatiotemporal distribution characteristics of power system voltage dynamics has gradually decreased. It is significant to reduce the power loss caused by error in identifying voltage dynamic spatiotemporal distribution characteristics. Hence it is necessary to design methods that can more accurately classify power system voltage dynamic spatiotemporal distribution characteristics data. This study proposes a method for studying the spatiotemporal distribution characteristics of power system voltage dynamics based on an improved random forest algorithm. The information entropy calculation method of decision tree in random forest algorithm is improved. According to the experimental results, the classification accuracy of the method for voltage dynamic spatiotemporal distribution characteristics is 99.55%. It can effectively achieve the dynamic spatiotemporal distribution of power system voltage.