The Impact of Hybrid Wet/Dry Cooling on Concentrating Solar Power Plant Performance

Author(s):  
Michael J. Wagner ◽  
Charles Kutscher

This paper examines the sensitivity of Rankine cycle plant performance to dry cooling and hybrid (parallel) wet/dry cooling combinations with the traditional wet-cooled model as a baseline. Plants with a lower temperature thermal resource are more sensitive to fluctuations in cooling conditions, and so the lower temperature parabolic trough plant is analyzed to assess the maximum impact of alternative cooling configurations. While low water-use heat rejection designs are applicable to any technology that utilizes a Rankine steam cycle for power generation, they are of special interest to concentrating solar power (CSP) technologies that are located in arid regions with limited water availability. System performance is evaluated using hourly simulations over the course of a year at Daggett, CA. The scope of the analysis in this paper is limited to the power block and the heat rejection system, excluding the solar field and thermal storage. As such, water used in mirror washing, maintenance, etc., is not included. Thermal energy produced by the solar field is modeled using NREL’s Solar Advisor Model (SAM).

Author(s):  
Mohammad Abutayeh ◽  
Anas Alazzam ◽  
Bashar El-Khasawneh

A scheme to streamline the electric power generation profile of concentrating solar power plants of the parabolic trough collector type is suggested. The scheme seeks to even out heat transfer rates from the solar field to the power block by splitting the typical heat transfer fluid loop into two loops using an extra vessel and an extra pump. In the first loop, cold heat transfer fluid is pumped by the cold pump from the cold vessel to the solar field to collect heat before accumulating in the newly introduced hot vessel. In the second loop, hot heat transfer fluid is pumped by the hot pump from the hot vessel to a heat exchanger train to supply the power block with its heat load before accumulating in the cold vessel. The new scheme moderately decouples heat supply from heat sink allowing for more control of heat delivery rates thereby evening out power generation.


2019 ◽  
Vol 141 (2) ◽  
Author(s):  
Mohammad Abutayeh ◽  
Kwangkook Jeong ◽  
Anas Alazzam ◽  
Bashar El-Khasawneh

A scheme to streamline the electric power generation profile of concentrating solar power (CSP) plants of the parabolic trough collector (PTC) type is suggested. The scheme seeks to even out heat transfer rates from the solar field (SF) to the power block (PB) by splitting the typical heat transfer fluid (HTF) loop into two loops using an extra vessel and an extra pump. In the first loop, cold HTF is pumped by the cold pump from the cold vessel to the SF to collect heat before accumulating in the newly introduced hot vessel. In the second loop, hot HTF is pumped by the hot pump from the hot vessel to a heat exchanger train (HXT) to supply the PB with its heat load before accumulating in the cold vessel. The new scheme moderately decouples heat supply from heat sink allowing for more control of heat delivery rates thereby evening out power generation.


Energies ◽  
2017 ◽  
Vol 11 (1) ◽  
pp. 37 ◽  
Author(s):  
Jose Rogada ◽  
Lourdes Barcia ◽  
Juan Martinez ◽  
Mario Menendez ◽  
Francisco de Cos Juez

Power plants producing energy through solar fields use a heat transfer fluid that lends itself to be influenced and changed by different variables. In solar power plants, a heat transfer fluid (HTF) is used to transfer the thermal energy of solar radiation through parabolic collectors to a water vapor Rankine cycle. In this way, a turbine is driven that produces electricity when coupled to an electric generator. These plants have a heat transfer system that converts the solar radiation into heat through a HTF, and transfers that thermal energy to the water vapor heat exchangers. The best possible performance in the Rankine cycle, and therefore in the thermal plant, is obtained when the HTF reaches its maximum temperature when leaving the solar field (SF). In addition, it is necessary that the HTF does not exceed its own maximum operating temperature, above which it degrades. The optimum temperature of the HTF is difficult to obtain, since the working conditions of the plant can change abruptly from moment to moment. Guaranteeing that this HTF operates at its optimal temperature to produce electricity through a Rankine cycle is a priority. The oil flowing through the solar field has the disadvantage of having a thermal limit. Therefore, this research focuses on trying to make sure that this fluid comes out of the solar field with the highest possible temperature. Modeling using data mining is revealed as an important tool for forecasting the performance of this kind of power plant. The purpose of this document is to provide a model that can be used to optimize the temperature control of the fluid without interfering with the normal operation of the plant. The results obtained with this model should be necessarily contrasted with those obtained in a real plant. Initially, we compare the PID (proportional–integral–derivative) models used in previous studies for the optimization of this type of plant with modeling using the multivariate adaptive regression splines (MARS) model.


2018 ◽  
Vol 10 (11) ◽  
pp. 3937 ◽  
Author(s):  
Sahar Bouaddi ◽  
Aránzazu Fernández-García ◽  
Chris Sansom ◽  
Jon Sarasua ◽  
Fabian Wolfertstetter ◽  
...  

The severe soiling of reflectors deployed in arid and semi arid locations decreases their reflectance and drives down the yield of the concentrating solar power (CSP) plants. To alleviate this issue, various sets of methods are available. The operation and maintenance (O&M) staff should opt for sustainable cleaning methods that are safe and environmentally friendly. To restore high reflectance, the cleaning vehicles of CSP plants must adapt to the constraints of each technology and to the layout of reflectors in the solar field. Water based methods are currently the most commonly used in CSP plants but they are not sustainable due to water scarcity and high soiling rates. The recovery and reuse of washing water can compensate for these methods and make them a more reasonable option for mediterranean and desert environments. Dry methods, on the other hand, are gaining more attraction as they are more suitable for desert regions. Some of these methods rely on ultrasonic wave or vibration for detaching the dust bonding from the reflectors surface, while other methods, known as preventive methods, focus on reducing the soiling by modifying the reflectors surface and incorporating self cleaning features using special coatings. Since the CSP plants operators aim to achieve the highest profit by minimizing the cost of cleaning while maintaining a high reflectance, optimizing the cleaning parameters and strategies is of great interest. This work presents the conventional water-based methods that are currently used in CSP plants in addition to sustainable alternative methods for dust removal and soiling prevention. Also, the cleaning effectiveness, the environmental impacts and the economic aspects of each technology are discussed.


Author(s):  
Brad Bullington

The power block for a conventional Concentrated Solar Power (CSP) Plant without thermal storage follows standard power block design practices. A closed loop heat transfer fluid (HTF) is heated in the solar field, which consists of multiple solar collector assemblies (SCAs). Heat exchangers use the heat from the HTF to generate and superheat steam. The steam is sent to a steam turbine, which generates electricity. The cooled HTF is recirculated back to the solar field. In an effort to shift the period of power generation or to maintain full power output during non-peak periods of operation, a thermal energy storage (TES) system can be added. This entails adding a second closed loop fluid that is heated by the HTF during sufficient radiation hours, which in turn can heat the HTF that is supplied to the power block during periods of non-peak radiation. This article discusses the process control and design issues for the integrated solar field, TES system and power block for these plants. The article will address the following: 1) Operations with the Solar field on-line, TES system off-line, and STG on-line. 2) Operations with the Solar field on-line, TES system charging, and STG on-line. 3) Operations with the Solar field on-line, the TES system discharging, and STG on-line. 4) Operations with the solar field off-line, the TES system discharging, and the STG on-line. 5) Operations with the Solar field on-line, the TES system charging, and STG off-line. 6) Steam Turbine Issues. 7) Freeze protection. 8) HTF/TES Heat Exchanger. 9) Circulating Water and Surface Condenser.


2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Massimo Moser ◽  
Franz Trieb ◽  
Jürgen Kern ◽  
Houda Allal ◽  
Nicolas Cottret ◽  
...  

Within the MED-CSD project, feasibility studies of integrated hybrid concentrating solar power (CSP) and seawater desalination (DES) plants were carried out in selected locations in Morocco, Italy, Cyprus, Egypt and Gaza/West Bank. After a review on CSP and desalination technologies, ten typical sites within the five partner countries have been selected. For each location, a CSP-DES plant was modeled. The model bases on hourly time series of solar irradiance, ambient temperature, as well as wind speed and includes local seasonal and hourly load curves for power and water. Surplus thermal energy from the solar field is fed into the energy storage, so that operation is possible at night and during cloud transients; gaps between demand and solar power production are covered by cofiring with fossil fuel. Different plant components (solar field collectors and desalination technologies) have been compared. A techno-economic model is applied in order to analyze the economic feasibility and the required financial framework conditions of the projects. Furthermore, an analysis of the market potential of concentrating solar power for sea water desalination in the Mediterranean Region and socio-economic and environmental impact analyses were implemented.


2021 ◽  
Vol 20 (1) ◽  
pp. 100
Author(s):  
A. E. Achiles ◽  
J. V. H. D’Angelo

Environmental concerns have been motivating the use of renewable energysources to meet sustainable requirements. In this context, concentrated solarpower driven by organic Rankine cycles has been classified as an up-andcomingtechnology to generate energy under low and moderate temperatures.In order to have a better understanding of the availability and utilization of thisenergy resource, the purpose of the present study is to perform acomprehensive energetic, exergetic and heat transfer analysis of a 200 kWsolar organic Rankine cycle through the presentation of the energy and exergyefficiencies and losses for each component; the exergy destruction at all stagesof the process; and the heat transfer behavior along the receiver. The thermalmodel was developed in Engineering Equation Solver and validated withliterature data. The solar collector was operated with Therminol 66 and theworking fluid employed in the power block was cyclohexane. The energeticefficiencies achieved in the solar field, power block, and overall system were64.97; 21.36; and 13.87 %, respectively. Considering the exergetic efficiencies,they were 27.37; 54.45; and 14.89 %, respectively. The solar resource variationshowed that the higher DNI value, the better the system performance.


Author(s):  
Joshua Schmitt ◽  
Jason Wilkes ◽  
Timothy Allison ◽  
Jeffrey Bennett ◽  
Karl Wygant ◽  
...  

In order to maintain viability as a future power-generating technology, concentrating solar power (CSP) must reduce its levelized cost of electricity (LCOE). The cost of CSP is assessed with the System Advisor Model (SAM) from the National Renewable Energy Laboratory (NREL). The performance of an integrally geared compressor-expander recuperated recompression cycle with supercritical carbon dioxide (sCO2) as the working fluid is modeled. A comparison of the cycle model to the integrated SAM cycle performance is made. The cycle model incorporates innovative cycle control methods to improve the range of efficiency, including inventory control. The SAM model is modified to accommodate the predicted cycle performance. The ultimate goal of minimizing the LCOE is targeted through multiple approaches, including the cost of the power block, the impact of system scale, the sizing of the thermal system relative to the power block system, the operating approach for changes in ambient temperature and availability of sunlight. Through reduced power block cost and a detailed cycle model, the LCOE is modeled to be 5.98 ȼ/kWh, achieving targeted techno-economic performance. The LCOE of the CSP system is compared to the cost of hybrid solar and fossil-fired systems. An analysis is made on the efficacy of a fossil backup system with CSP and how that relates to potential future costs of carbon dioxide emissions.


Sign in / Sign up

Export Citation Format

Share Document