A Solar-Powered Direct Steam Generation Boiler for an Educational Desktop Rankine Cycle

2011 ◽  
Author(s):  
Ximena Toro ◽  
Marc Compere ◽  
Bernard Van Wie ◽  
Birce Dikici
Keyword(s):  
Power Systems ◽  
Solar Power ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Steam Generation ◽  
Concentrated Solar Power ◽  
Absorber Plate ◽  
Power Cycle ◽  
Direct Steam ◽  
Solar Powered

This paper presents the design and hardware validation of a unique solar powered boiler for powering a desktop scale steam Rankine power cycle. The primary purpose of the desktop Rankine cycle is to improve engineering education through a hands-on laboratory learning approach. Within this context, we have designed and validated a novel, glass-enclosed boiling chamber that generates steam entirely from the sun. Using a solar concentrator, the sun’s heat is focused onto an absorber plate that acts as a heating element. The absorber plate receives solar power via radiation and heats the working fluid through convection. Since this is a direct steam generation boiler, the entering fluid is water that stratifies upon boiling into two steady-state flow regions with both liquid and gaseous phases. A thermal model is developed to characterize the concentrated solar power (CSP), chamber geometry, and heat transfer to the working fluid. A complete solar-to-steam efficiency analysis is presented and validated with the hardware. The boiler’s estimated efficiency is 27.7% for converting typical daily solar irradiance to steam. The solar water boiling process can clearly be observed and is an excellent educational tool for both concentrated solar power as well as Rankine cycle power systems.

Sintering of Solid Particulates Under Elevated Temperature and Pressure in Large Storage Bins for Thermal Energy Storage

2014 ◽  
Author(s):  
R. C. Knott ◽  
D. L. Sadowski ◽  
S. M. Jeter ◽  
S. I. Abdel-Khalik ◽  
H. A. Al-Ansary ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Size Distribution ◽  
Thermal Energy ◽  
Solar Power ◽  
Physical Characteristics ◽  
Working Fluid ◽  
Concentrated Solar Power ◽  
Power Cycle ◽  
Solid Particulates ◽  
Storage Bins

This research is a part of the DOE-funded SunShot project on “High Temperature Falling Particle Receiver.” Storing thermal energy using solid particulates is a way to mitigate the time of day dependency of concentrated solar power. Small particles may be stored easily, and can be used as a heat transfer medium to transfer heat to the power cycle working fluid through a heat exchanger. This study examines the physical characteristics of solid particulates of different materials kept inside large storage containers. Particle behavior at the expected high temperatures of the concentrated solar power cycle combined with the elevated pressure experienced within the storage container must be evaluated to assess the impact on their physical properties and ensure that the particles would not sinter thereby impacting flow through the system components particularly the receiver and heat exchanger. Sintering is a process of fusing two or more particles together to form a larger agglomerate. In the proposed concentrated solar power tower design, particles will experience temperatures from 600°C to 1000°C. The increase in temperature changes the physical characteristics of the particle, along with any impurities that could form particle to particle bonds. In addition, the hydrostatic pressure exerted on particles stored inside a storage unit increases the probability of sintering. Thus, it is important to examine the characteristics of particles under elevated temperatures and pressures. The experimental procedure involves heating particulates of a known mass and size distribution to temperatures between 600°C and 1000°C inside a crucible. As the temperature is held constant, the particulate sample is pressed upon by a piston pushing into the crucible with a known constant pressure. This process is repeated for different temperatures and pressures for varying lengths of time. The resulting particulates are cooled, and their size distribution is measured to determine the extent of sintering, if any, during the experiment. The particulates tested include various types of sand, along with alumina particles. The data from this experiment will allow designers of storage bins for the solid particulates to determine when significant sintering is expected to occur.

scholarly journals A novel approach to thermal storage of direct steam generation solar power systems through two-step heat discharge

2019 ◽  
Vol 236 ◽  
pp. 81-100 ◽  
Author(s):  
Jing Li ◽  
Guangtao Gao ◽  
Cagri Kutlu ◽  
Keliang Liu ◽  
Gang Pei ◽  
...  
Keyword(s):  
Power Systems ◽  
Solar Power ◽  
Thermal Storage ◽  
Steam Generation ◽  
Novel Approach ◽  
Direct Steam

scholarly journals Research on Performance Test Characteristics of Solar Energy ORC Generator Set

2018 ◽  
Vol 232 ◽  
pp. 04007
Author(s):  
Yongkang Zhang ◽  
Jinghui Song ◽  
Yunfeng Xia
Keyword(s):  
Heat Transfer ◽  
Power Generation ◽  
Heat Source ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Source Condition ◽  
Power Cycle ◽  
Solar Powered ◽  
Regenerative Cycle

In order to study the performance of low-temperature solar-powered ORC generator sets, a solar-powered ORC power generation test bench was designed and built. In the experiment, R-123 was used as the organic Rankine cycle working fluid, and the solar ORC power generation system was experimentally studied. The research results show that when the direct solar radiation intensity is about 400W, the temperature of the heat transfer oil at the outlet of the collector can reach 140 °C. When the temperature of the heat transfer oil at the outlet of the collector is around 110°C, the collector efficiency of the collector can reach about 60%. Under the heat source condition, when the power cycle part is switched from the basic cycle to the regenerative cycle mode, the collector heat collection efficiency can reach about 60%. Under the heat source condition, when the power cycle part is switched from the basic cycle mode to the regenerative cycle mode, the measured efficiency is increased from 9.3% to 10.8%, and the measured cycle efficiency is increased from 1.57% to 1.67%, which is an increase of 6.07%. The measured cycle system efficiency is about 10%, and the heat recovery mode is slightly higher than the basic cycle mode. The organic Rankine cycle performance under different working fluid flows was also investigated in the experiment. The maximum measured average power was 386.27 W when the working fluid flow was 6.88 kg·s. At a certain heat source temperature, as the flow rate of the working fluid increases, the inlet pressure of the expander increases, and the circulating output work also increases. Under a certain working fluid flow rate, as the temperature of the heat source increases, the temperature of the inlet of the expander increases, and the inlet pressure increases. the cycle output work also increased.

scholarly journals A METHODOLOGY FOR SIMULATION AND ASSESSMENT OF CONCENTRATED SOLAR POWER PLANTS

2016 ◽  
Vol 15 (1) ◽  
pp. 33
Author(s):  
A. R. Starke ◽  
L. F. L. Lemos ◽  
S. Colle ◽  
R. F. Reinaldo ◽  
J. M. Cardemil ◽  
...  
Keyword(s):  
Power Plants ◽  
Solar Power ◽  
Steam Generation ◽  
Concentrated Solar Power ◽  
Power Block ◽  
Receiver System ◽  
Direct Steam ◽  
Fluid Properties ◽  
Solar Power Plants ◽  
Concentrated Solar Power Plants

A thermal analysis of Concentrated Solar Power plants is conducted considering parabolic trough collectors (PTC), linear Fresnel collectors using direct steam generation scheme (LFC-DSG) and central receiver system using both molten nitrate salts (CRS-MNS) direct steam generation (CRS-DSG). The plant capacities were ranged from 50 to 800 MWth and the analysis focuses on the environmental conditions of selected locations in South America. Thus, the study considers a parametric analysis of the main design parameter for different plant scales, in terms of the thermal performance indicators as solar field aperture area, power block rating capacity and plant annual efficiencies. The annual production of the plants is calculated by using the Transient System Simulation program (TRNSYS), which considers a new component library developed for that purpose. This library is based in the open access models developed by the U.S National Renewable Energy Laboratory and currently employed by the System Advisor Model (SAM) program. In addition, a new fluid properties subroutine compatible with TRNSYS codes standards was developed, which uses the freeware CoolProp library. These approaches allowed to modify and create new configurations for CSP plants, e.g. thermal storage for the DSG scheme.

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