Performance Analysis of a Modular Air Cooled Condenser for a Concentrated Solar Power Plant

Author(s):  
J. Moore ◽  
R. Grimes ◽  
E. J. Walsh

The use of air cooled condensers in power generation facilities is increasing in arid regions around the world. There is a specific requirement for more efficient air cooling technologies to be developed for Concentrated Solar Power (CSP) plants. This paper aims at determining the effects of various condenser design features on CSP plant output. In particular this paper considers a modular condenser and focuses on designing a suitable compact heat sink to be coupled with a variable speed fan array. Tube banks with radial fins have been used for decades to heat and cool gases and numerous correlations exist to predict the performance of such a heat exchanger. The initial design of this air-cooled condenser is essentially a tube bundle consisting of 6 rows of helically finned round tubes in an equilateral staggered arrangement. A laboratory-scale steady state test facility was designed to investigate the accuracy of the relevant correlations for the given design. Due to an undesired phenomenon which exists in multi-row condensers known as backflow, an investigation was performed to analyze the performance of the tube bank with fewer tube rows. The thermal and hydraulic performance for a tube bundle with a different number of tube rows was measured and found to be within 10–18% of the existing correlations. New correlations for heat transfer and pressure drop for the given design are presented for greater accuracy in the calculation of the condenser performance. These correlations, based on the measured data were combined with performance characteristics from a steam turbine to model the thermodynamic plant performance incorporating the various condenser designs. The investigation shows that for each condenser size, design and ambient temperature, an optimum fan speed exists which maximizes plant output. Further analysis shows that for a 1000 module condenser, a 4 row condenser results in the highest plant output, with a loss in efficiency due to condenser operation of 1.85%. A 2 row condenser also performs relatively well with 600 or more modules. This analysis shows that a condenser consisting of a series of such modules, can tightly control and optimize the net plant output power by simply varying fan speed.

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Luis Coco Enríquez ◽  
Javier Muñoz-Antón ◽  
José María Martínez-Val Peñalosa

The objective of this investigation is the comparison between supercritical ethane (s-ethane, C2H6) and supercritical carbon dioxide (s-CO2) Brayton power cycles for line-focusing concentrated solar power plants (CSP). In this study, CSP are analyzed with linear solar collectors (parabolic trough (PTC) or linear Fresnel (LF)), direct molten salt (MS), or direct steam generation (DSG) as heat transfer fluids (HTF), and four supercritical Brayton power cycles configurations: simple Brayton cycle (SB), recompression cycle (RC), partial cooling with recompression cycle (PCRC), and recompression with main compression intercooling cycle (RCMCI). All Brayton power cycles were assessed with two working fluids: s-CO2 and s-ethane. As a main result, we confirmed that s-ethane Brayton power cycles provide better net plant performance than s-CO2 cycles for turbine inlet temperatures (TITs) from 300 °C to 550 °C. As an example, the s-ethane RCMCI plant configuration net efficiency is ∼42.11% for TIT = 400 °C, and with s-CO2 the plant performance is ∼40%. The CSP Brayton power plants were also compared with another state-of-the-art CSP with DSG in linear solar collectors and a subcritical water Rankine power cycle with direct reheating (DRH), and a maximum plant performance between ∼40% and 41% (TIT = 550 °C).


2013 ◽  
Vol 24 (1) ◽  
pp. 77-89 ◽  
Author(s):  
Thomas Telsnig ◽  
Ludger Eltrop ◽  
Hartmut Winkler ◽  
Ulrich Fahl

Concentrated solar power (CSP) plants can play a major role in the future South African electricity mix. Today the Independent Power Producer (IPP) Procurement Programme aims to facilitate renewable energy projects to access the South African energy market. In spite of this incentive programme, the future role of CSP plants in South Africa has yet to be defined. Using hourly irradiance data, we present a new method to calculate the expected yield of different parabolic trough plant configurations at a site in each of Gauteng and the Northern Cape, South Africa. We also provide cost estimates of the main plant components and an economic assessment that can be used to demonstrate the feasibility of solar thermal power projects at different sites. We show that the technical configurations, as well as the resulting cost of electricity, are heavily dependent on the location of the plant and how the electricity so generated satisfies demand. Today, levelised electricity costs for a CSP plant without storage were found to be between 101 and 1.52 ZAR2010/kWhel, assuming a flexible electricity demand structure. A CSP configuration with Limited Storage produces electricity at costs between 1.39 and 1.90 ZAR2010/kWhel, whereas that with Extended Storage costs between 1.86 and 2.27 ZAR2010/kWhel. We found that until 2040 a decrease in investment costs results in generating costs between 0.73 ZAR2010/kWhel for a CSP plant without storage in Upington and 1.16 ZAR2010/ kWhel for a configuration with Extended Storage in Pretoria. These costs cannot compete, however, with the actual costs of the traditional South African electricity mix. Nevertheless, a more sustainable energy system will require dispatchable power which can be offered by CSP including storage. Our results show that the choice of plant configuration and the electricity demand structure have a significant effect on costs. These results can help policymakers and utilities to benchmark plant performance as a basis for planning.


Author(s):  
David G. Teraji

One of the most promising renewable energy concepts is the Concentrated Solar Power (CSP) tower with a hybrid combined cycle gas turbine power block. U.S. Department of Energy studies [4] indicate that this type of system can achieve greater than 60% thermal efficiency and result in a lower the levelized cost of electricity (LCOE) as compared to the CSP technology operating today. The air Brayton gas turbine part of the combined cycle system can also operate in a hybrid mode with natural gas resulting in optimizing the plant performance and making it available for fully dispatchable power output even when the solar thermal is not available. Since this concept had not been tested on a MW scale, a CSP tower hybrid gas turbine demonstration plant called Solugas was built near Seville, Spain. A 4.6 MW Mercury™ 50 gas turbine was modified to operate with a high temperature air receiver. The demonstration tests were conducted to ensure the turbine can operate over a broad range of conditions with and without solar energy. The performance and operation safety were critical test objectives. The demonstration test results were excellent and met all program objectives.


2019 ◽  
Vol 13 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Mladen Bošnjaković ◽  
Vlado Tadijanović

More recently, there has been an increasing interest in the use of concentrated solar thermal energy for the production of electricity, but also for the use in cogeneration and trigeneration. In this sense, the increasing use of solar thermal energy in urban areas is expected, and its impact on the environment is inducing an increasing interest. The paper analyses the impact of concentrated solar power technology (linear Fresnel, parabolic trough, parabolic dish, and central tower) on the environment in terms of water consumption, land use, wasted heat, emissions of gases, emissions of pollutants that include the leakage of heat transfer fluid through pipelines and tanks, impact on flora and fauna, impact of noise and visual impact. The impact on the environment is different for different concentrated solar power technologies and depends on whether thermal energy storage is included in the plant. Water is mainly used for cooling the system, but also for cleaning the surface of the mirror. To reduce water consumption, other cooling technologies (e.g. air cooling) are being developed. The available data from the literature show large variances depending on the size of the plant, geographic location and applied technology.


Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 575 ◽  
Author(s):  
Soomro ◽  
Mengal ◽  
Memon ◽  
Khan ◽  
Shafiq ◽  
...  

In Pakistan, the utilization of renewable energy sources is increasing in order to reduce the electricity supply and demand gap. However, concentrated solar power (CSP) generation has not been considered in the country even though it has gained considerable attention worldwide. This study, as such, investigates the potential, performance, and economic analyses of four CSP technologies for different locations in Pakistan. Initially, an assessment of CSP sites, including solar resource, land, and water availability, was undertaken. Then, performance simulations of CSP technologies for four different locations of Pakistan, namely Quetta, Hyderabad, Multan, and Peshawar, were examined. For all cases, highest energy production was achieved in summers and lowest in winters, and CSP plants with evaporative cooling were found to be efficient compared to air cooling. The results also revealed that the Quetta and Hyderabad regions were promising for CSP development while parabolic tough (PT) and solar power tower (SPT) were the suitable CSP technologies for these regions. Specifically, the SPT plant with air cooling could be a favorable option for energy production in Quetta. Lastly, economic analyses revealed the financial feasibility of CSP plants in Pakistan since the levelized cost of energy is found to be significantly low.


2017 ◽  
Vol 8 (4) ◽  
pp. 1-19
Author(s):  
Oliveira Helio Marques de ◽  
◽  
Giacaglia Giorgio Eugenio Oscare ◽  

2012 ◽  
Vol 57 (4) ◽  
pp. 911-920
Author(s):  
Bernard Nowak ◽  
Zbigniew Kuczera

Abstract The present paper introduces a method for calculating the thermal power of DV-290 mining air cooler’s evaporator. The power usually differs from the nominal power given by the manufacturer. The thermodynamic parameters of cooled air are not obtained as a result of in situ measurements, but in indirect manner that is by determining the evaporation and condensation’s pressure values of R407C refrigerant. The pressure dependencies formulated as a function of air enthalpy at the evaporator’s inlet were obtained using calculations of a computer program which solves the system of equations describing heat and mass transfer in the refrigerator’s compressor on the basis of previous measurements of air performed before and after its cooling. The obtained dependencies are demonstrated in a graphical (fig. 2 and fig. 3) and analytical (the regression equations (19) and (20)) manner, the values of correlation coefficients are also presented. For the known evaporation and condensation pressure values of the refrigerant, and thus for its basic physical parameters the complete thermal power of the evaporator was determined, that is its: air cooling overt power, dehumidification occult power, temperature, relative humidity and specific humidity of air after its cooling. In addition, using the mentioned method, the capacity of DV-290 refrigerator’s evaporator is provided for the given thermodynamic parameters of air before cooling, along with air thermodynamic parameters after cooling.


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