Annual Average Output Research Articles

Mathematical modelling and optimizing design of heliostat field

The heliostat field is a form of solar thermal power plant, The heliostat field is a crucial component of solar thermal power plants and establishing a heliostat field is of great significance for reducing carbon emissions. and is of great significance in reducing carbon emissions This paper focuses on the mathematical modeling and optimization design problem of the heliostat field. For three different design scenarios, firstly, based on the data provided by the China Undergraduate Mathematical Contest in Modeling 2023, a geometric optical efficiency model is proposed to determine the annual average optical efficiency and output thermal power under specific heliostat field design parameters. Secondly, aiming at the optimal design parameters of the solar furnace field under the condition of rated annual average output thermal power is 60 MW\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ ext{MW}$$\\end{document}, Particle Swarm Optimization (PSO) combing with efficiency model is utilized to determine the optimal design parameters of the heliostat field. Finally, this paper uses Quasi-Monte Carlo ray tracing (QMCRT) model to perform simulations, exploring how to obtain the optimal design parameters of the heliostat field with the goals of maximizing the output thermal power and ensuring high efficiency. Furthermore, the influence of normal disturbances on the annual average annual average thermal output power is investigated.

Research on Optimization Design of Heliostat Field Based on Ray Tracing

In tower-type solar thermal power generation systems, the optical efficiency of the mirror field is the primary factor determining the overall system's power generation efficiency. In order to meet the requirement of a rated power of 60MW with different heliostat sizes and installation heights, optimize the various parameters of the heliostat field, establish a tower-type solar thermal power generation system model, and evaluate the model. Taking the maximum annual average output power per unit mirror area as the optimization objective, through simulation, it is found that the heliostat with a side length of 6 meters, a gradient design of installation height, a regular triangular layout, and the use of ray tracing technology can efficiently capture solar energy. The average optical efficiency, average cosine efficiency, average shadow blocking efficiency, average truncation efficiency, and average thermal power factor per unit area mirror are analyzed. The research results show that there is an optimal combination of absorber northward movement, heliostat size, equilateral triangle arrangement, installation height gradient design, and solar trajectory, which enables the annual average output thermal power to reach or even exceed the rated power of 60MW.This model and algorithm compared and analyzed genetic, greedy, and simulated annealing algorithms on the same dataset. The runtime is approximately 8-10 minutes, with CPU utilization around 60%.

Research on the annual average thermal power of heliostat field in tower solar energy

The concentrating mirror field is a concentrating and heat collecting subsystem in the tower solar thermal power station, and its optical performance directly affects the solar energy utilization efficiency of the power station. In this paper, the coordinate system of heliostat field and single heliostat is established, and the grid division technology is introduced to describe its reflection effect on sunlight and its occlusion. In this paper, the shadow occlusion loss that affects the optical efficiency is divided into three parts, including incident light occlusion loss, reflected light occlusion loss and absorption tower shadow occlusion loss. For any time, the output power of the heliostat near the solar direction is small, while the output power of the heliostat far away from the solar direction is large. Compared with other influencing factors, the cosine loss has the greatest influence on the heliostat field, and the center of the absorption tower installed in the circular heliostat field is obtained. The size of the heliostat is a square with a side length of 6m, the installation height is 4m, and the annual average optical efficiency is 0.6216 when the position of the heliostat is determined. The annual average output thermal power is 36.3958 MW, and the annual average output thermal power per unit mirror area is 0.5794 .

A Parameter Optimization Design and Numerical Calculation Method for Circular Heliostat Field

Solar energy is a low-carbon, eco-friendly, clean energy source that is easily converted into heat and electricity, making the study of solar thermal power generation technology of great significance and with broad application prospects. To improve the performance of solar power plants, it is necessary to reasonably arrange the light reflectors. Both denser heliostats are needed to ensure enough light can be concentrated into the solar collector, thereby improving the power of the power station; at the same time, waste of material must be prevented, striving to increase output thermal power per unit mirror area. This paper is based on the background of the 2023 CUMCM Problem A. Firstly, it analyzes parameters such as the optical efficiency of the original heliostat field, the annual average output power, and the annual average thermal power output per unit mirror area. Secondly, based on the data provided in the appendix, it analyzes the distribution pattern of the heliostat field and establishes an optimization design model for the heliostat field. Next, the optimization design model of the heliostat field is solved using discrete numerical calculation methods. Finally, according to the results of the model solution, the placement positions of the heliostats, the size of the mirrors, and the installation height are adjusted to improve the annual average thermal power output per unit mirror area, thereby achieving an optimized design of the heliostat field.

Enhancing Heliostat Field Performance: A Comprehensive Study on Optical Efficiency and Annual Thermal Power

The many advantages of solar photovoltaic technology make it bound to be commercially competitive in the coming years, and its development is strategically important. The parameters of the heliostat field, including the positional coordinates of the absorber tower, the size and mounting height of the heliostat mirrors, as well as the number and position of the heliostat mirrors, are designed according to the requirement of the rated annual average thermal power output of 60 MW so that the heliostat field will have the largest possible annual average thermal power output per unit of mirror area under the condition of reaching the rated power. Larger sizes and higher mounting heights of heliostats help to capture more solar energy and thus increase the annual average output thermal power per mirror area. The efficiency and output thermal power of heliostats of different sizes and mounting heights are evaluated by simulating the numerical calculation method and the best combination is found.

Optimization Design of Heliostat Field Based on Biomathematical Models

The optimal design of heliostat field in solar power generation device is studied Heliostat field generates high temperature by focusing the sunlight reflected from the mirror surface, thus pushing the turbine to generate electricity. In order to improve the efficiency of power generation, this paper optimizes the parameters of heliostat field, establishes a single-objective optimization model, and uses mixed strategy whale optimization algorithm to solve it. Through geometric optical analysis and ray tracing model, the optical efficiency of heliostat field and the annual average output thermal power per mirror area are calculated. Finally, through the discussion and analysis of the model, the optimization design method is evaluated

Simulation of performance differences between offshore and land‐based photovoltaic systems

AbstractThe purpose of this study is to model, simulate, and compare the performance of a photovoltaics system on land and at sea. To be able to have a fair comparison the effect of sea waves, wind speed and relative humidity are considered in this model. The sea waves are modeled in the frequency domain, using a wave spectrum. The irradiation on a tilted surface for a floating system is calculated considering the tilt angle that is affected by the sea waves. Moreover, the temperature is estimated based on heat transfer theory and the natural cooling system for both floating and land‐based photovoltaic systems. Actual measured weather data from two different locations, one located at Utrecht University campus and the other one on the North Sea, are used to simulate the systems, thus making the comparison possible. Energy yield is calculated for these weather conditions. The results show that the relative annual average output energy is about 12.96% higher at sea compared with land. However, in some months, this relative output energy increases up to 18% higher energy yield at sea.

Cd Balance Analysis of a Typical Rice Paddy System in Central Hunan

By conducting field positioning experiments, we studied the development trend of Cd pollution in a typical paddy system. The samples of atmospheric deposition and irrigation water were collected monthly from November 2015 to November 2018 during which fertilizer, soil, and rice samples were also collected. The Cd concentration in the samples was monitored and analyzed to conduct research on the balance between Cd inputs and outputs in a typical paddy system in Hunan Province. The results suggest that through irrigation water, atmospheric deposition and fertilizer, the average annual input of Cd in the paddy field system is 8.735 g·(hm2·a)-1, of which atmospheric deposition, the major source, accounts for 69.15%-82.04% of the total input, with an average of 76.61%. This is followed by irrigation water and fertilizer, respectively, accounting for 12.62%-23.66% and 5.34%-7.19%, with an average of 16.94% and 6.45%, respectively. Through surface runoff, soil infiltration and the rice harvest of the aboveground portion, the annual average output of Cd contained in the paddy system is 7.093 g·(hm2·a)-1. Rice harvest accounts for 85.27%-95.02% of the total output, with an average of 89.69%; surface runoff accounted for 4.57%-13.96% of the total output, with an average of 9.41%; and soil infiltration accounted for 0.41%-1.51% of the total output, with an average of 0.90%. The study indicates that Cd contained in paddy systems in Central Hunan exhibits a net input, and the soil Cd pollution is increasing as a result. Straw returning and straw removal have an important impact on the soil Cd balance, and straw removal can slow the trend of soil Cd pollution accumulation.

Simulation model of a new solar laser system of Fresnel lens according to real observed solar radiation data in Helwan of Egypt

A new simulation model of a new solar pumped laser system was tested to be run in Helwan in Egypt (latitude φ=29°52′N, longitude λ=31°21′E and elevation=141m) as an example of an industrial polluted area. The system is based on concentrating the solar radiation using a Fresnel lens on a laser head fixed on a mount tracking the sun during the day and powered by a DC battery. Two cases of this model are tested; the first one is the model consisting of a Fresnel lens and a two-dimensional Compound Parabolic Concentrator (CPC), while the other is the model consisting of a Fresnel lens and a three-dimensional Compound Parabolic Concentrator (CPC). The model is fed by real actual solar radiation data taken in Helwan Solar Radiation Station at NRIAG in the various seasons in order to know the laser power got from such a system in those conditions. For the system of Fresnel lens and 2D-CPC, an average laser output power of 1.27W in Winter, 2W in Spring, 5W in Summer and 4.68W in Autumn respectively can be obtained. Accordingly, the annual average output power for this system is 3.24W. For the system of Fresnel lens and 3D-CPC, an average laser output power of 3.28W in Winter, 3.55W in Spring, 7.56W in Summer and 7.13W in Autumn respectively can be obtained. Accordingly, the annual average output power for this system is 5.38W.

Calculation of forest potential productivity for Tianshan forest region

Forest Potential Productivity (FPP) of 8 counties in Tianshan was calculated, and the potential timber output of these counties was analyzed with Miami Model and Thornthwaite Memorial Model. Research results showed that annual average output of present stand in Tianshan Forest Region was 3.7 m3/(hm2.a), which reached only 49% of average FPP.