Power Boosting Research Articles

Thermodynamic and economic analyses of nuclear power plant integrating with seawater desalination and hydrogen production for peak shaving

An integrated system incorporating a nuclear unit, multi-stage flash desalination, and proton exchange membrane electrolyzer is proposed for peak shaving. The extraction steam is used for seawater desalination to produce freshwater, the generator output power is employed to drive the electrolyzer for hydrogen production, and the electrolyzer outlet water heats the feedwater for power boosting. Thermodynamic analysis shows that 53.76 MW is used for seawater desalination-hydrogen production (electrolyzer voltage =2.0 V). The system efficiency is 37.44 % with output hydrogen energy of 37.86 MW, and the specific energy consumption is 4.72 kWh/Nm3. The electrolyzer exergy efficiency of the integrated system is 81.94 %, higher than the standalone electrolyzer with 61.17 %. Sensitivity analysis shows higher voltage and lower water flow rates are conducive to higher hydrogen production rates. Economic analysis shows that the cost of hydrogen production is 15.16 CNY/kg and the annual net income can reach 7.68·106 CNY.

Integration of Steam Recovered from Molten Salts in a Solar Integrated Combined Cycle

In the current context of the energy transition, Integrated Solar Combined Cycle (ISCC) power plants are an alternative that are able to reduce carbon emissions from combined cycle (CC) power plants. In addition, the coupling to an energy storage system based on molten salts benefits hybridization, allowing the energy surplus to be to stored to cover peaks in energy demand. Because it is a recent technology, the determination of the optimal injection points for the solar-generated steam into the combined cycle is a critical issue. In this work, a thermodynamic model of a hybrid natural gas and solar thermal CC power plant has been developed using Thermoflex to analyze the integration effects in terms of efficiency and power. For all the steam injection candidate positions, the effects of ‘power boosting’ and ‘fuel saving’ operation modes have been simulated, considering operation conditions that are compatible with the useful range of molten salts. The results show that injection of steam at the high-pressure line before the steam turbine increases the cycle’s gross efficiency with respect to the reference case, estimating a reduction of carbon emissions of 6696 kg/h in the ‘fuel saving’ mode and an increase in gross power of 14.4 MW in the ‘power boosting’ mode. Hence, adapting current combined cycles for hybridization with solar power is a viable solution in the transition period towards more sustainable energy sources.

Surrogate Modeling and Aeroelastic Analysis of a Wind Turbine with Down-Regulation, Power Boosting, and IBC Capabilities

As the maturity and complexity of wind energy systems increase, the operation of wind turbines in wind farms needs to be adjustable in order to provide flexibility to the grid operators and optimize operations through wind farm control. An important aspect of this is monitoring and managing the structural reliability of the wind turbines in terms of fatigue loading. Additionally, in order to perform optimization, uncertainty analyses, condition monitoring, and other tasks, fast and accurate models of the turbine response are required. To address these challenges, we present the controller tuning and surrogate modeling for a wind turbine that is able to vary its power level in both down-regulation and power-boosting modes, as well as reducing loads with an individual blade control loop. Two methods to derive the setpoints for down-regulation are discussed and implemented. The response of the turbine, in terms of loads, power, and other metrics, for relevant operating conditions and for all control modes is captured by a data-driven surrogate model based on aeroelastic simulations following two regression approaches: a spline-based interpolation and a Gaussian process regression model. The uncertainty of the surrogate models is quantified, showing a good agreement with the simulation with a mean absolute error lower than 4% for all quantities considered. Based on the surrogate model, the aeroelastic response of the entire wind turbine for the different control modes and their combination is analyzed to shed light on the implications of the control strategies on the fatigue loading of the various components.

A novel solar tower assisted pulverized coal power system considering solar energy cascade utilization: Performance analysis and multi-objective optimization

Solar-assisted pulverized coal power systems offer higher solar energy utilization efficiency, enabling pulverized coal power plants to rapidly achieve energy-saving and emission-reduction targets. This study proposes the incorporation of two solar heaters to create a new solar tower assisted pulverized coal power (STPCP) system for the cascade utilization of solar energy. A comprehensive performance analysis, considering both power-boosting (PB) and fuel-saving (FS) operation modes, has been conducted. The multi-objective particle swarm optimization method is then applied to optimize the system from both thermal and economic perspectives. The findings demonstrate that in FS mode, annual coal consumption decreases by 24.35 × 103 tons, while in PB mode, annual power generation increases by 94.12 GWh. The optimization analysis demonstrates that the optimal cost of electricity (COE) and annual standard coal consumption rate in PB mode are 1.4 × 10−4 USD/kWh and 4.3 g/kWh lower than those in FS mode. Additionally, as the solar field cost declines, the optimal COE and annual standard coal consumption rate gradually decrease. While, increasing coal prices result in higher optimal COE, but lower optimal annual standard coal consumption rate. Based on this study, it can be inferred that the STPCP system shows promising prospects in the future.

Influence of water‐methanol injection and turbocharging on the performance of a hydrogen‐fueled spark ignition engine

AbstractThis article presents a study that compares the performance and emission characteristics of a four‐stroke, four‐cylinder spark ignition (SI) engine fueled by gasoline and neat hydrogen. The engine was equipped with turbocharging to optimize ignition timing for power boosting and vaporized water–methanol injection to reduce emissions. Engine tests were conducted at speeds ranging from 2000 to 6000 rpm, with a fixed intake pressure and varying quantities of hydrogen and spark advance timings. The study compared the results of non‐turbocharged and turbocharged engines with water–methanol injection in terms of combustion, performance, and emissions. The findings showed that the turbocharged water–methanol hydrogen operation had a higher brake thermal efficiency (BTE) than its counterpart, while the brake power of the hydrogen engine operation increased with turbocharging but slightly decreased with water–methanol injection. Additionally, volumetric efficiency improved by 7% for turbocharged and 4% for water‐injected hydrogen engine operation compared to the counterpart. The cylinder pressure for turbocharging with water–methanol operation yielded 16.32% higher compared with counterpart gasoline engine operation. Finally, nitrogen oxides (NOx) emissions were reduced with turbocharging and water–methanol injection compared to the counterpart non‐turbocharged hydrogen engine operation.

Performance assessment of a solar aided dual-fuel supercritical steam power plant for power boosting under different operating loads

Fuel supply due to political conflict and decarbonization is the most challenging standup for the energy sector and electricity generation. Therefore, the present study introduces a thermodynamic analysis for a modeled supercritical solar aided power plant (SAPP) using two types of fuel at different operating loads, i.e., 50%, 75%, and 100%. The proposed SAPP is investigated in terms of energy, exergy, and steam flow rates to verify the advantages of using SAPP over conventional power plants. In the SAPP, the condensate water passes into the heat exchangers using a working fluid of Therminol VP-1. Additionally, the turbine extraction steam at 100% load is minimized, and it is eliminated at 50% and 75% loads. The results show that the recovered amount of feed water extraction increases the mechanical power for SAPP-based natural gas in comparison with the conventional supercritical steam power plant by 16, 21, and 9.7% at an operating load of 50%, 75%, and 100%, respectively. Consequently, SAPP-based natural gas maintains an increase in the overall energy efficiency compared with the CPP of 13.7, 17, and 1.9% at an operating load of 50%, 75%, and 100%, respectively. As well, the mechanical power of the SAPP-based oil fuel increases compared with CPP by 25.7, 27.6, and 17.4% at 50%, 75%, and 100% loads, respectively. Whereas, the overall energy efficiency enhances due to using the SAPP-based oil fuel compared with that of the CPP by 20.6, 21.9, and 7% at a load of 50%, 75%, and 100%, respectively.

Fractal structured charge-excitation triboelectric nanogenerators for powering portable electronic devices.

Effective power management on the outputs of triboelectric nanogenerators (TENGs) is critical for their practical applications due to the large impedance and unbalanced load matching. Recently proposed voltage multiplying circuits for external-charge excitation and self-charge excitation are usually unstable and require reversal for device restarting and common switched-capacitor-converters usually cause large switching losses. In this work, we fabricated a fractal structured charge-excitation circuit for TENGs using diodes and capacitors. The fractal switched-capacitor-converter coupled with voltage regulator diodes can greatly boost the output charge and current of the TENG without reverse starting. The managed output performance of the TENG can be controlled by the electronic component parameters and external operating frequency. Through the component and condition optimization, the fractal structured charge-excitation TENG (FSC-TENG) can achieve nearly 5.8 times charge boosting and almost 16.8 times power boosting in the pulsed mode. Furthermore, the FSC-TENG successfully drove a hygrothermograph and was integrated into a yoga mat for harvesting human-body motion energy to power an electronic watch and a pedometer. The FSC-TENG with good charge accumulation properties and stability is a promising candidate for practical self-powered applications.

Over 10-kW fiber laser spectral beam combination based on dichromatic mirrors

Owing to the advantages of good beam quality, high conversion efficiency, convenient thermal management and compact structure, high power fiber lasers have been widely desired in industrial processing. So far, the output power has been strictly limited by the nonlinear effects and transverse mode instability. In order to break through the power limitation, here we experimentally demonstrate a power boosting technology called spectral beam combination based on dichromatic mirrors. Firstly, high power fiber amplifiers with different central wavelengths are established for the spectral combination. Secondly, utilizing a dual-beam combined system and two homemade high power fiber amplifiers, an output power of 10 kW is achieved, with a remarkable combination efficiency of 98.3% and a beam quality of <i>M</i> <sup>2</sup>～1.33. Secondly, using a three-beam combined system, an output power of 13.5 kW is obtained with a combination efficiency of 96.8% and beam quality of <i>M</i> <sup>2</sup>～1.61. By increasing the number of input beams and their output power as well, we believe that a higher output power can be achieved based on dichromatic mirror spectral beam combination.

A 260-GHz Four-Way Phase Compensated CMOS Frequency Multiplier Chain

A novel × 6 frequency multiplier chain with a center frequency of 260 GHz is developed in 40 nm CMOS and measured through this work. The multiplication is accomplished through an × 3 frequency multiplier followed by a doubler successive stage. A four-way signal combiner is employed to enhance the output power, whereas phase shifters are dedicated for compensating the possible phase deviations between the different combined ways, and consequently maintain the combining efficiency. For further output power boosting, the output matching network of 260-GHz frequency doubler is optimized, and a stacked amplifier with 11.5 dBm is employed as a driving amplifier. The multiplier has been fabricated and a peak output power of 3.0 dBm is measured at 260 GHz with a 3-dB bandwidth of 17 GHz.

Performance analysis of a novel mode using solar energy to recycle and reuse water vapor from flue gas of coal-fired power station

Coal-fired power stations need to use massive quantities of coal and discharge substantial amounts of pollutants every year. Coupling solar energy with traditional coal-fired power stations can solve these problems. Most studies focus on using solar energy to heat boiler inlets, feedwater and high-temperature steam. However, areas with more solar energy are often water-deficient areas and saving water resources is particularly important. In this study, a 600 MWe coal-fired power station and solar energy are combined into a solar-aided coal-fired power generation (SACPG) system. Five SACPG systems are studied. There are parallel steam heating, reheating, double reheating, heating feedwater before pump and recycle and reuse water vapor from flue gas. For the first time propose using solar energy to recycle and reuse water vapor from the flue gas of coal-fired power stations in power-boosting (PB) and fuel-saving (FS) modes to analyze its thermal characteristics, exergy characteristics and energy savings. The research shows that feedwater recycle mode has the largest total thermal efficiency, which is 42.47 % and boiler thermal efficiency of 95.02 %. Three operation modes of saving water scheme including feedwater recovery, reheat steam recovery and FS mode are considered in this paper. Among three modes, FS has the smallest exergy loss of all parts, except fans. The FS mode coal saving rate is 10.79 g/kWh and the water saving rate is 3.87 × 105 t per year. The PB mode water saving rate is 4.04 × 105 t per year. Feedwater recycling output is larger than that of reheated steam recycling. The mode with the highest total thermal efficiency, largest solar field exergy efficiency and coal saving rate is using solar energy to heat feedwater parts and parallel steam generation employing thermal solar energy, which are 42.76 %, 27.70 % and 15.53 g/kWh, respectively. Using thermal solar energy to heat feedwater prior to the feedwater pump offers the highest boiler thermal efficiency (94.44 %) and the lowest exergy loss of all parts except fans. Using solar energy to heat high-temperature parts, the reheated steam mode has the largest boiler thermal efficiency, total thermal efficiency and solar field exergy efficiency, which are 94.16 %, 43.68 % and 33.61 % respectively and the smallest exergy loss of all parts, except fans. Meanwhile, the double reheated steam mode has the largest coal saving rate, which is 9.60 g/kWh.

System Analysis and Design Space Exploration of Regional Aircraft with Electrified Powertrains

This paper explores the design spaces of a thin-haul and a regional aircraft with parallel hybrid-electric propulsion architectures for a 2030 entry into service date. Notional technology reference aircraft models were developed for a 19- and a 50-passenger aircraft based on publicly available data on Beechcraft 1900D and ATR 42-600, respectively. A set of airframe and propulsion system technologies projected to reach maturity by 2030 was infused into the aircraft models. Parametric, physics-based models were created for the charge-depleting hybrid architecture. Different modes of operation were identified and parameterized with a range of design variables to investigate the feasibility and trade space for peak power shaving, climb power boosting, electric taxi, battery usage schedules, and in-flight battery recharge strategies. Thousands of electrified aircraft concepts with varying electrification, operation, and technology scenarios were sized under the same system-level requirements as their conventional counterpart. The resulting multidisciplinary design space exploration environment was used to identify the optimum vision system designs and modes of operation for the minimum block fuel-burn objective. It has been found that both vehicle classes with the charge-depleting parallel hybrid electric architecture provided fuel-burn benefits over their 2030 advanced technology counterparts under certain operational modes.

Reassessment of different flat TCO integrated reflectors for the crystalline silicon solar PV module in view of its longer operational life

AbstractIn the present simulation work with experimental validation, the performance of a transparent conductive oxide (TCO) film‐coated spectrally selective reflector in the low‐concentrated photovoltaic application has been analysed. The use of mirrors in solar photovoltaic (PV) applications is a well‐established thing. However, it increases the operating temperature and requires more thermally stable, expensive solar modules. In this regard, for the first time, commercially available TCO‐coated glasses such as fluorine‐doped tin oxide (FTO) and indium tin oxide (ITO) have been integrated with mirrors. The spectrally selective reflector is a promising technology to achieve a high‐power yield from the commercially available crystalline silicon photovoltaic (C‐Si PV) module during its lifetime. They have the property to absorb unwanted photons in the region of the AM1.5 spectrum (1200 to 2000 nm), which partially thermalises the solar module through plasmonic absorption. The present study found that the proposed approach helps to restrict the increase in PV module temperature caused by the reflected rays from a mirror. The electrical performance of a standalone C‐Si PV was compared with that of the same system after the addition of FTO, ITO and a conventional mirror system. Our analysis indicates that, with the mirror integration, the degradation rate can increase to 1.5% per year if the standalone PV module's ageing rate is 0.8% per year. Through FTO incorporation with the same, the ageing rate has been reduced by up to 1.18% per year due to a reduction in temperature. This result is quite interesting, considering that spectrally selective reflectors do not stop high‐energy photons from thermalizing the PV module. The entire work has been done on commercially available materials, which makes it easier and ready to be implemented in large PV plants.Highlights A spectrally selective mirror for PV power boosting. Transparent conductive oxide (TCO) glass integration with mirror reduces the IR concentration approximately 50%. The reduction in thermalisation of PV module from the mirror by 3–5°C. This integration increases the PV module operational life by at least 4 years compared with commercial mirror.

A Hybrid Solar-Gas Turbine Combined-Cycle with Absorption Inlet-Air Cooling as a Decarbonizing and Power Boosting Solution: Energy and Environment Analyses

A Hybrid Solar-Gas Turbine Combined-Cycle with Absorption Inlet-Air Cooling as a Decarbonizing and Power Boosting Solution: Energy and Environment Analyses

Output power boosting of a photovoltaic panel based on various back pipe structures: a computational study

The efficiency of photovoltaic panels (PV) drops due to the rise in temperature, which leads to a decrease in the PV output power. A PV/Thermal system is therefore used as a solution to increase the output power from the PV panels. Comsol Multiphysics software program, a simulator-based Finite Element Method (FEM) tool, and Matlab program simulations are used to perform this electro-thermal model. The simulation process for different back pipes follows a serpentine, and a new shape of pipes called (square shapes) which are attached under the PV module. These shapes were specifically chosen for higher conversion efficiency and increase the heat transfer of the system. Additionally, a comparison between electrical parameters and heat transfer characteristics of water and CuO/water nanofluid in a PV cooling system has been studied. The new shape leads to improve the photovoltaic (PV) module parameters, such as short circuit current ISC, open-circuit voltage VOC, and maximum power Pmax for a new shape more than the serpentine shape. These parameters are calculated under Air Mass 1.5 G (AM1.5G) with 1000 W/m2 of irradiance which is considered the average irradiance at the MENA (The Middle East and North Africa) region throughout the year. The results exhibit the PV module’s total enhancement by using the new shape with CuO nano-fluid about 24.7 %.

Improved calendar disc scheduler for LTE advanced networks with HARQ

Long Term Evolution Advanced (LTE-A) is a broadband wireless technology that supports variety of services with different data rate. In order to achieve this the evolved Node B (eNB) uses different features provided in the 3GPP standards. Features like Carrier Aggregation (CA), Multiple input and Multiple output (MIMO) and Hybrid Automatic Repeat Request (HARQ) help to increase the throughput and spectral efficiency. In this paper, a novel two-level calendar disc algorithm with HARQ is introduced at the eNB for effectively scheduling real time and non-real time traffic with different service types. The algorithm also uses a burst profile management module that analyzes the current user profile and notifies the scheduler about the need to change in profile based on power boosting. The Calendar Disc Scheduler (CDS) is improved by adding HARQ retransmission index as a parameter in calculating the metric weight. The scheduler was tested for both adaptive and non-adaptive methods of HARQ in both synchronous and asynchronous modes. The proposed improved CDS scheduler was simulated with LTESim simulator and compared with calendar disc algorithm without HARQ improvements. Results show that the proposed scheduling method provides increased performance in terms of goodput, delay and spectral efficiency.

An Investigation of Hybrid Solar-Steam Power Plant: A case study in Iraq

In this work integrating Al-Zubaydia (Kut-Iraq) thermal power plant with solar thermal system is studied for heating feed water by solar energy to reduce fuel consumption and greenhouse gases emission. A closed type Parabolic Trough Solar Collector (PTSC) is designed, constructed, instrumented, and tested. Its thermal characteristics are reported under Iraq climate conditions for the period extended from June, to September 2017. The collector heat gain, efficiency, absorber temperature and heat exchanger effectiveness (considered as feed water heater) were presented for absorber side flow rates of (0.15, 0.2, 0.3, 0.4, 0.5) lpm of water or oil), and shell side water flow rates of (0.4, 0.5, 0.6lpm). Results show that the maximum obtained thermal efficiency of parabolic trough solar collector was 83.33% for oil working fluid. The maximum obtained oil outlet temperature was 106 oC at solar noon for (0.15) lpm. Theoretical results showed that the fuel save mode needs collector area of (32842 m2), while that needed for power boosting is (102569 m2) for the same thermal cycle efficiency. The fuel save mode reported a reduction in greenhouse emission.

Comparative Performance Assessment of 300 MW Solar‐Coal Hybrid Power Generation System Under Different Integration Mechanisms

Solar−coal hybrid power generation (SCHPG) system is one of the interesting solutions for solar power generation. This research aims to find a more viable integration mechanism of solar energy into a coal‐fired thermal power plant in terms of techno‐economic and ecology perspective. Performance of the 300 MW SCHPG system in the nominal and part‐load condition is analyzed under three different integration mechanisms. Numerical simulation of 300 MW SCHPG system is investigated under four different cases using a thermal balance approach. Operation modes of fuel‐saving (FS) and power‐boosting (PB) are considered for each case. Among the proposed cases, Case 4 is obtained as a good operation performance, which is recommended as the main case. The solar energy in Case 4 is used for evaporating feedwater and steam superheating, and steam reheating. Results show that the optimal aperture area of the heliostat solar field is 330 330 m2, and the minimum levelized cost of electricity is 0.1847 USD kWh−1. In Case 4, thermal efficiency is increased by 7.19% with standard coal consumption reduced by 45.3 g kWh−1 compared to a reference power plant. In the SCHPG system, coal consumption is reduced by 26.8 tons h−1 in FS mode, whereas power output is increased 30 MW h−1 in PB mode.

Power boosting of a combined cycle power plant in Jordan: An integration of hybrid inlet cooling & solar systems

Many developing countries like Jordan, suffer from the lack of natural resources required to supply their energy demand. As such, maximum utilization of the available energy and renewable resources becomes a necessity. ALQatrana powerplant in Jordan; operating on a combined cycle suffers from sensitivity to ambient air temperatures and the lack of full utilization of waste heat of the flue gas. In this work, the plant was simulated using the engineering equation solver, and the simulation was validated against the actual powerplant data. A cascade of absorption and mechanical chillers for inlet air cooling, along with a CSP system were proposed. These auxiliary systems were also simulated and validated against literature, then integrated with the actual power plant cycle. Results showed that using the hybrid system for inlet air cooling with a combined cycle, can be more appealing in terms of power boosting and economical profit, compared to using either alone. The proposed system showed a relative increase in power by 22.8%, a 4.3% increased efficiency, and a relative decrease in SFC by 8.4%, compared to the actual power plant. Moreover, due to the hybrid inlet air cooling unit, the system exhibited low sensitivity to variation in ambient temperatures; hence, a stable power augmentation with relative change of only 0.9% over the range of temperatures (10–50) ℃. Additionally, compared to a duct burner integration, the proposed system, led to 6.4 million dollars annual saving in fuel consumption, with a 15% less CO2 emission for equivalent power production. A comprehensive feasibility study was also performed; showing a return of investment period equal to 5.3 years, which is very promising.

Analysis of heat flow diagram of small-scale power generation system: Innovative approaches for improving techno-economic and ecological indices

In this paper, the heat flow diagram of steam turbine model K-6-35 has been analyzed for innovative approaches towards improving the techno-economic and ecological indices of the small-scale power generation system. The numerical analysis is performed using IPSEpro process simulation software based on heat balance method under four different cases. It was found that the study of Solar Assisted Power Generation (SAPG) system has important practical significance in power generation with minimum pollutants and maximum efficiency. Both fuel-saving (FS) and power-boosting (PB) operation modes of the SAPG system are considered. Various types of stand-alone solar thermal power plants exhibited very low overall efficiency with many ecological advantages compared to the conventional thermal power plant based on fossil fuels. Besides, SAPG system with FS mode presented higher techno-economic indices and operation performance. An important reduction in fuel consumption and pollutant emissions could be obtained with SAPG system. Considering the hourly, daily, monthly, and yearly amount of saved fuel and reduced pollutants in the whole power plant, the SAPG system with FS mode can largely contribute to high ecological indices power generation. A thermal efficiency increased by 1.31% with specific equivalent fuel consumption decreased by 22.54 g/kWh was obtained with SAPG system. The coal consumption was reduced by 4.75% when SAPG system operates in FS mode.

A general and simple method for evaluating the performance of the modified steam Rankine cycle: Thermal cycle splitting analytical method

Steam Rankine cycle is the most widely used power cycle for the electric power generation and its process modification can effectively improve the power generation efficiency. To evaluate the thermal performance of these process modifications, the “thermal cycle splitting analytical method” was proposed and illustrated by general formulas. In this analytical method, the modifications of the thermal power cycle are classified into two types, i.e., “power boosting” and “heat saving”; then, the modified cycle is split into a basic cycle and one/several equivalent power cycle(s) (EPC) with simpler thermodynamic process; finally, the effect of the modification can be reflected by the split EPCs, which will not need the overall system simulation. Based on the proposed analytical method, the high-temperature EPCs and low-pressure EPCs were split from the reheat and regenerative cycles, respectively, and the corresponding models for evaluating the efficiency of the modified cycle were developed. Then, the proposed analytical method was utilized to investigate several representative modifications of a typical 1000 MW-stage supercritical power plant, including the cycle itself modification (double reheat, multi-stage regeneration, outer steam cooler, regenerative turbine) and the external heat integration (boiler cold-end energy integration, coal pre-drying and solar-aid power generation), and the obtained results showed a high accuracy through comparing with the overall system simulation. The proposed analytical method might provide a new perspective to analyze the energy saving mechanism of the complex thermal power cycles in a clearer and simpler way.