Experimental Investigation of Direct Steam Generation Dynamics in Solar Fresnel Collectors

2021 ◽  
Vol 143 (5) ◽  
Author(s):  
Marwan Mokhtar ◽  
Christian Zahler ◽  
Robert Stieglitz
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Steam Generator ◽  
Experimental Results ◽  
Steam Generation ◽  
Thermal Plant ◽  
Direct Steam ◽  
Solar Field ◽  
Economic Considerations

Abstract Direct steam generation (DSG) is a technology used to produce steam from a solar concentrated thermal plant directly in the solar field without the use of an intermediate steam generator. This technology is attractive due to economic considerations but is technically challenging. In this brief, the results of an experimental study of DSG dynamics are presented. The study provides a detailed description of these effects supported by experimental results and suggests ways to coping with them.

scholarly journals A Direct-Steam Linear Fresnel Performance Model for NREL’S System Advisor Model

2012 ◽  
Author(s):  
Michael J. Wagner ◽  
Guangdong Zhu
Keyword(s):  
Heat Loss ◽  
Mathematical Formulation ◽  
Model Performance ◽  
Performance Model ◽  
Electricity Production ◽  
Steam Generation ◽  
Time Step ◽  
Wide Range ◽  
Direct Steam ◽  
Solar Field

This paper presents the technical formulation and demonstrated model performance results of a new direct-steam-generation (DSG) model in NREL’s System Advisor Model (SAM). The model predicts the annual electricity production of a wide range of system configurations within the DSG Linear Fresnel technology by modeling hourly performance of the plant in detail. The quasi-steady-state formulation allows users to investigate energy and mass flows, operating temperatures, and pressure drops for geometries and solar field configurations of interest. The model includes tools for heat loss calculation using either empirical polynomial heat loss curves as a function of steam temperature, ambient temperature, and wind velocity, or a detailed evacuated tube receiver heat loss model. Thermal losses are evaluated using a computationally efficient nodal approach, where the solar field and headers are discretized into multiple nodes where heat losses, thermal inertia, steam conditions (including pressure, temperature, enthalpy, etc.) are individually evaluated during each time step of the simulation. This paper discusses the mathematical formulation for the solar field model and describes how the solar field is integrated with the other subsystem models, including the power cycle and optional auxiliary fossil system. Model results are also presented to demonstrate plant behavior in the various operating modes.

Direct Steam Generation in Parabolic Troughs: First Results of the DISS Project

2002 ◽  
Vol 124 (2) ◽  
pp. 134-139 ◽  
Author(s):  
M. Eck ◽  
W.-D. Steinmann
Keyword(s):  
Steady State ◽  
Controller Design ◽  
Experimental Results ◽  
Phase Flow ◽  
Simulation Studies ◽  
Steam Generation ◽  
Two Phase ◽  
State Tests ◽  
Direct Steam ◽  
First Results

This article presents the latest experimental results of the European DISS (DIrect Solar Steam) project. The experiments are subdivided into steady state and transient tests. The goal of the steady state tests is the investigation of the thermohydraulic phenomena of the occurring two phase flow, whereas the transient tests are needed for the controller design. The experimental results are compared to simulation studies. Implications for the plant operation will be discussed.

scholarly journals A Direct Steam Generation Solar Power Plant With Integrated Thermal Storage

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Jürgen Birnbaum ◽  
Markus Eck ◽  
Markus Fichtner ◽  
Tobias Hirsch ◽  
Dorothea Lehmann ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Storage System ◽  
Thermal Storage ◽  
Market Potential ◽  
Steam Generation ◽  
Parabolic Trough ◽  
Power Block ◽  
Direct Steam ◽  
Solar Field ◽  
Operating Points

For the future market potential of parabolic trough power plants with direct steam generation (DSG), it is beneficial to integrate a thermal storage system. Heat storage media based on phase change materials offer heat transfer at constant temperatures needed for the evaporation process. Different options for a plant layout are presented and discussed. The interactions between the three subsystems—solar field, power block, and thermal storage—are analyzed, and boundary conditions arising from the thermal storage system are identified. Compared with a system without storage the number of operating points increases significantly since different combinations of storage charge and discharge operations go along with a varying power output of the solar field. It is shown that the large number of theoretical operating points can be reduced to a subset with practical relevance. Depending on the live steam parameters a reheat is necessary within the power block. Compared with parabolic trough fields with a single phase heat transfer medium such as oil, a special heat exchanger configuration is needed for a DSG plant. Different alternatives based on available technologies are presented and evaluated.

Experimental Study on Ductility and Dissipative Capacity of AAC Block Load Bearing Walls

2011 ◽  
Vol 90-93 ◽  
pp. 1096-1099
Author(s):  
Jing Hai Yu ◽  
Shou Xiang Wu
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Deformation Behavior ◽  
Experimental Results ◽  
Load Bearing ◽  
Static Test ◽  
Load Displacement ◽  
Better Than

Based on the experimental investigation of quasi-static test of 6 AAC block walls and obtain the load-displacement experimental results, the deformation behavior and dissipative capacity of the walls due to different height to width ratios and vertical pressing stresses are studied and analyzed, the comparisons and analyses with other block walls’ deformation behavior are also carried out. The results indicate that AAC block walls’ dissipative capacity is directly proportional with vertical pressing stresses and the deformation behavior is otherwise, the diversification of height to width ratios can change the breaking form of block walls and affect on ductility and dissipative capacity. The ductility of AAC block walls is better than other block walls.

scholarly journals Experimental Investigation of Heat Losses from a Heat Pipe Based Parabolic Trough Collector used for Direct Steam Generation

2021 ◽  
pp. 31-39
Author(s):  
Abiem Louis Tersoo ◽  
Akoshile Clement Olufemi
Keyword(s):  
Experimental Investigation ◽  
Thermal Efficiency ◽  
Glass Tube ◽  
Heat Losses ◽  
Solar Thermal ◽  
Thermal System ◽  
Steam Generation ◽  
Parabolic Trough ◽  
Direct Steam ◽  
Solar Thermal System

The performance of a thermosiphon based parabolic trough collector (PTC) used for direct steam generation depends largely on the heat losses of the solar thermal system. This paper presents an experimental investigation of the heat losses in a thermosiphon based solar thermal system that used a linear receiver with a PTC for the generation of low temperature steam. A locally constructed PTC was used to concentrate sun rays to a linear copper pipe enclosed in an evacuated glass tube and held at the focal line of the PTC to heat water and generate steam. Circulation of the water in the closed-loop solar thermal system was through natural convection. A solar meter was used to measure the incident radiation flux at the experimental site and PT100 temperature sensors were installed at different points of the system to measure the temperature distribution within the system. The thermal efficiency and overall heat losses of the system were investigated by fitting the experimental data to standard equations. The results showed that the instantaneous thermal efficiency of the system was 46.48%, 43.1% and 45.32% respectively for three days examined. The overall heat losses in the system were 1211.95, 974.32 and 911.26 kwh per day respectively for the three days investigated. Heat losses from the tank accounted for over 83% of the losses for all the days examined. The evacuated glass tube reduced heat losses from the receiver to very low values of 2.31, 1.63 and 1.43 KWh per day respectively for the three days tested. The use of a better insulating material on the tank was recommended to reduce convective and conductive heat losses, thereby enhancing the performance of the system.

Study of Different Configurations of ISCC Parabolic Trough

2014 ◽  
Author(s):  
Dolores Duran ◽  
Rafael Almanza ◽  
Ivan Martínez
Keyword(s):  
High Pressure ◽  
Power Plants ◽  
Low Pressure ◽  
Pressure Level ◽  
Combined Cycle ◽  
Design Parameters ◽  
Steam Generation ◽  
Parabolic Trough ◽  
Direct Steam ◽  
Solar Field

This work shows the study of different configurations of integrated solar combined cycle (ISCC) parabolic-trough power plant with Direct Steam Generation (DSG). This paper is a sequel of previous works (Duran), but in this case six different configurations are analyzed: two pressure level without reheater (2P), 2P considering the solar field the high pressure economizer of the heat recovery steam generator, 2P considering the solar field the low pressure superheater, two pressure level with reheater (2PR), 2PR considering the solar field the low pressure superheater, 2PR considering the solar field the high pressure economizer. The main objective is to achieve the thermoeconomic optimization (based on Thermodynamic 1st. Law) of the HRSG including the solar field, to determine the optimal design parameters of both systems. It is applied a genetic algorithm (GA) methodology employed in previous works for the optimization of combined cycle power plants. Also, a sensitivity analysis with respect to the variation of solar radiation is done for the configurations that yield better results. As a result it would be obtained the optimal parameters of the HRSG and the optimal solar energy contribution for the configurations analyzed.

Performance Analysis of Direct Steam Generation-Central Receiver Systems

2012 ◽  
Author(s):  
Javier Sanz-Bermejo ◽  
José Gonzalez-Aguilar ◽  
Manuel Romero
Keyword(s):  
Power Plants ◽  
Superheated Steam ◽  
System Analysis ◽  
Live Steam ◽  
Saturated Steam ◽  
Steam Generation ◽  
Central Receiver ◽  
Power Block ◽  
Direct Steam ◽  
Solar Field

This work presents a comparative study between direct steam generation central receiver solar power plants working at live steam conditions similar to those found in commercial plants. PS10 and PS20 by Abengoa Solar use a single-receiver, producing saturated steam, whereas Sierra SunTower by e-Solar and Ivanpah Solar Electric Generating System (ISEGS) by BrightSource use dual-receiver technology producing superheated steam. The system analysis includes individual studies for each subsystem: solar field, receiver and Rankine power block; as well as the overall-analysis of a 66.7 MWth plant. PS10 working conditions were analysed with and without intermediate reheat step. It was assumed that Sierra SunTower-configuration has non-reheat turbine and Ivanpah-cycle includes an intermediate reheat step. The reheat process in PS10 configuration was performed using a fraction of live steam coming from the receiver; while for Ivanpah-configuration exhaust steam from high pressure turbine stage was sent back to the superheated steam section of the dual-receiver. These concepts make possible to avoid hybridisation and assure special regimes (such as Spanish feed-in tariff). The analysis of the heliostat field for dual-receiver concepts reveals that the aiming strategy on the absorbers has not relevant influence on optical performances. However, receiver efficiency decreased from 91.9%, working with saturated steam, to 87.86–84.14% working with superheated steam related to operating temperatures and heat exchange surface area. This study reveals that the improvement achieved in the power block under Ivanpah configuration was able to compensate higher thermal losses at the receiver, increasing net power production by 25.5% compared with saturated steam conditions.

scholarly journals Experimental results of 2018 test campaign of the ALSOLEN 450 prototype for direct steam generation and thermal storage

2020 ◽  
Author(s):  
Valéry Vuillerme ◽  
Pierre Garcia ◽  
Pascal Aubouin ◽  
Adrien Camus ◽  
Elena Carnacina ◽  
...  
Keyword(s):  
Thermal Storage ◽  
Experimental Results ◽  
Steam Generation ◽  
Direct Steam

Analyzing Solar Power Plant Performance Through Data Mining

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Henryk Maciejewski ◽  
Loreto Valenzuela ◽  
Manuel Berenguel ◽  
Jesús Fernández-Reche ◽  
Konrad Adamus ◽  
...  
Keyword(s):  
Data Mining ◽  
Latent Variables ◽  
Principal Component ◽  
Plant Performance ◽  
Solar Power Plant ◽  
Steam Generation ◽  
Thermal Plant ◽  
Direct Steam ◽  
Mining Methods ◽  
Generation Facility

This work is devoted to application of data mining methods for monitoring of state of a solar thermal plant. The methods discussed are illustrated by example of a study performed for the DISS direct steam generation facility at the Plataforma Solar de Almeria (Spain). In order to deal with the problems of large dimensionality and high correlation among the data the methods of latent variables, principal component analysis and partial least squares, were applied. Results showed that normal and abnormal states during plant operation could be identified.

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