scholarly journals CFD Simulation of a 3D Solar Chimney Integrated with an Axial Turbine for Power Generation

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5771
Author(s):  
Suad Hassan Danook ◽  
Hussein A. Z. AL-bonsrulah ◽  
Ishak Hashim ◽  
Dhinakaran Veeman

The solar chimney is one of the uninvestigated areas in the possible selection in the field of renewable solar energy utilization. CFD can be demonstrated as a useful tool of figure confidence in the design and employment of a solar chimney. A realistic numerical model for a solar-based updraft power plant for power generation was established through this research work. Iraqi weather in Kirkuk, northern Iraq was considered for this case study. A three-dimensional (3D) simulation of the main geometric dimensions of the Spanish, Manzanares model integrated with a real turbine was performed using computational fluid dynamics (CFD). The turbulent model of RNG k-e, the nongrey discrete coordinate (DO) radiation model, and the solar raytracing algorithm were used. It was observed that the air velocity below the turbine was graded according to the seasons of the year and was at its maximum in July with 18.28 m/s due to the high ambient temperature, and the lowest value was recorded in January with 8.64 m/s. The overall average daily and monthly energy production values for the Kirkuk system were higher than those of the Kubang system, with values of 310 kWh/day and 9314 kWh/month, respectively, for the Kirkuk system, and 246 kWh/day and 7398 kWh/month, respectively, for the Kubang system. The simulation results showed that the electricity generation from the Kirkuk city power plant varied seasonally to be at its maximum value of 14,424 kWh/month in July. This research work will help to determine the possibility of producing electricity in this Kirkuk city, which would then contribute in a great way to reduce the cash spent on electricity.

Author(s):  
Sreelekha Arun

The energy consumption on global scale is continuously increasing, resulting in rapid use of energy resources available. Solar chimney power generation technology hence began to get growing attention as its basic model needs no depleting resources like fossil fuels for its functioning but only uses sunlight and air as a medium. It takes the advantage of the chimney effect and the temperature difference in the collector that produces negative pressure to cause the airflow in the system, converting solar energy into mechanical energy in order to drive the air turbine generator situated at the base of the chimney. Solar Chimney Power Plant (SCPP) brings together the solar thermal technology, thermal storage technology, chimney technology and air turbine power generation technology. However, studies have shown that even if the chimney is as high as 1000 m, the efficiency achievable is only around 3%. Hence, this review paper intents to put together the new technological advancement that aims to improve the efficiency of SCPP.


Author(s):  
Kai Wang ◽  
Houlin Liu ◽  
Shouqi Yuan ◽  
Minggao Tan ◽  
Yong Wang ◽  
...  

A double blades pump is widely used in sewage treatment industry, while at present the research on the internal flow characteristics of the double blades pump is very few. So, the CFD technology and the stereo PIV test technique are applied to study the inner flow in a double blades pump whose specific speed is 110.9. The commercial code FLUENT is used to simulate the inner flow in the double blades pump at 0.6Qd, 0.8Qd, 1.0Qd, 1.2Qd and 1.4Qd. The RNG k-ε turbulence model and SIMPLEC algorithm are used in FLUENT. According to the results of the three-dimensional steady numerical simulation, the distributions of velocity field in the impeller are obtained at the five different operating conditions. The analysis of the numerical simulation results shows that there is an obvious vortex in the impeller passage at off-design conditions. But the number, location and area of the vortex are different from each operation condition. In order to validate CFD simulation results, the stereo PIV is used to test the absolute velocity distribution in the double blades pump at Jiangsu University. The distributions of three-dimensional absolute velocity field at the above five different operating conditions are obtained by the PIV test, and the measured results are compared with the CFD simulation results. The comparison indicates that there are vortexes in impeller passages of the double blades pump under the five operating conditions. But as to the area of the vortex and the relative velocity values of the vortex core, there are some differences between the experiment results and the numerical simulation results. The research work can be applied to instruct the hydraulic design of double blades pumps.


Author(s):  
Duan Liqiang ◽  
Lv Zhipeng ◽  
Wang Zhen

Abstract The integrated solar energy-driven chiller combined cycle system (SCCC) has a problem of low annual solar energy utilization. The solar thermal efficiency and power output of the traditional integrated solar combined cycle system (ISCC) are limited by the integrated solar mirror field area and Rankine cycle efficiency. This paper presents a new system, on the basis of the combined cycle system with the three pressure HRSG with reheat, the solar energy is integrated into the chiller for cooling the compressor inlet air of gas turbine and the heat recovery steam generator (HRSG) for increasing the power output simultaneously. The Aspen Plus, TRNSYS and EBSILON softwares are applied in this paper to build the models of the overall system. The solar thermal efficiency, annual solar power generation and annual solar thermal efficiency are used to evaluate the performances of the new system, the traditional ISCC system and SCCC system. During the summer solstice, the proportions of solar energy used in cooling and heating are set as 40% and 60% in new system, respectively. The research results show that the new system has a higher power output (406.37MW), thermal cycle efficiency (53.61%) and solar thermal efficiency (48.85%) compared with the traditional ISCC system (385.63MW, 51.67%, and 24.43%, respectively) at the design point. The new system can regulates the proportions of solar energy used in the chiller and HRSG based on the monthly meteorological data, in order to maximize the annual solar energy utilization and annual solar power generation. The new system’s annual solar energy utilization hours (2071h) and solar power generation (25.863GW·h) are far greater than those of SCCC system (1498h, 18.185GW·h, respectively). Therefore, the proposed new system with the simultaneous integrations of solar energy with both the chiller and HRSG not only greatly increases the utilization rate of solar energy, but also has the significant thermodynamic advantages.


2016 ◽  
Vol 15 (1) ◽  
pp. 41
Author(s):  
J. C. Restrepo ◽  
O. J. Venturini ◽  
E. E. Silva ◽  
L. A. Cortabarria

The solar energy is one of the most promising energy sources expected for the future, due at their huge potential and the wide availability around the world. However, nowadays this important source of energy is not being harnessed or even addressed in their full potential. According to the last statements, it is important to develop solar energy conversion systems of high efficiency, as well as spreading its use in other forms besides the traditional systems of electric power generation or heating systems. For this reason, in this paper, it is explored the production of hydrogen through solar energy utilization, and the later electrical energy production by burning the produced hydrogen in a combined cycle power plant. The process was modelled for 3 MWe of electricity generation, and using the organic Rankine cycle. The main process for producing hydrogen from water using solar energy is based on a two steps redox thermochemical cycle, which has a theoretical conversion efficiencies of 54% at 1600 K. It is expected that this paper could contributed to the development of ways to enable a better integration of the solar energy with the current electricity generation technologies, as well as to incentive the use of the hydrogen as a clean fuel.


Hydro and thermal power plants are planned to reduce the overall operation cost of the thermal power plants by optimally allocating the hydro units and thermal units in the power generation system. In this research work a combined particle swarm optimization (PSO) and improved bacterial foraging algorithm (IBFA) is proposed for short term hydro thermal scheduling (STHTS) with prohibited operating zones (POZs). The PSO algorithm yields the fastest convergence rate and possesses maximum capability of finding the global optimal solutions to the HTS (Hydro Thermal Scheduling) problems. Also BFA has succeeded in solving several issues in optimization, but it demonstrates poor convergence characteristics for large-scale issues such as the STHTS problem. Critical improvements to the basic BFA are implemented to tackle this complex issue in view of its high-dimension search space. The chemotactic step is changed in IBF, so that the convergence becomes dynamic rather than static. The combined PSO-IBF algorithm is assessed on a typical power generation plants consists of a hydroelectric power plant and an equivalent thermal power plant with a time slot of six 12-hour intervals and simulated using the MATLAB software. The simulation result shows that the combined PSO-IBF algorithm yields minimum cost value and optimal convergence rate than the existing algorithms.


2017 ◽  
Vol 3 (2) ◽  
pp. 7
Author(s):  
Pragya Singh ◽  
Aayushi Priya

Economic Load Dispatch, ELD can be defined as the way of allocating the load level to the generators of the power plant in such a way that the total demand would be supplied in a most economic manner and completely. In a practical power system, the power plants are not located at the same distance from the centre of loads and their fuel costs are different. Also, under normal operating conditions, the generation capacity is more than the total load demand and losses. Thus, there are many options for scheduling generation. In an interconnected power system, the objective is to find the real and reactive power scheduling of each power plant in such a way as to minimize the operating cost. This means that the generator‟s real and reactive powers are allowed to vary within certain limits so as to meet a particular load demand with minimum fuel cost. This is called optimal power flow problem. In this paper, Economic Load Dispatch (ELD) of real power generation is considered. Economic Load Dispatch (ELD) is the scheduling of generators to minimize total operating cost of generator units subjected to equality constraint of power balance within the minimum and maximum operating limits of the generating units. This paper gives a survey of research work covering the concept of economic load dispatch. Economic load dispatch gives the best saving in cost for any power generation plant operation in which the methodology can be applied by various means from conventional to the advanced. In the past years up to 90s, the conventional techniques were used to make this happen but in the past decades AI techniques have fulfilled the requirements with satisfactory results that are being reviewed.


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