Conceptual Design and Analysis of Hydrocarbon-Based Solar Thermal Power and Ejector Cooling Systems in Hot Climates

2014 ◽  
Vol 137 (2) ◽  
Author(s):  
TieJun Zhang ◽  
Saleh Mohamed
Keyword(s):  
Power Systems ◽  
Low Cost ◽  
Thermal Power ◽  
Density Ratio ◽  
Solar Thermal ◽  
Working Fluid ◽  
Absolute Pressure ◽  
Low Grade ◽  
Alternative Refrigerants ◽  
Promising Alternative

A combined thermal power and ejector refrigeration cooling cycle is proposed in this paper to harness low-grade solar energy. It explores the possibility of utilizing abundant and low-cost hydrocarbon as the working fluid. Hydrocarbon fluid has been identified as a promising alternative to existing high global-warming-potential (GWP) refrigerants (i.e., HFCs) in next-generation cooling and organic thermal power systems. Several typical alternative refrigerants are evaluated by considering their fundamental thermophysical properties: absolute pressure level, volumetric cooling capacity, surface tension, saturated liquid/vapor density ratio, and kinematic viscosity. Comparing with R1234yf, R1234ze, and R744 (CO2), hydrocarbon refrigerants, such as R290 (propane) and R601 (pentane), do have inherent advantages for either cooling or power generation purposes in hot climates. Fundamental phase stability and transition issues have been considered in designing hydrocarbon ejectors for combined power and cooling cycles operating at high ambient temperature. Thermodynamic energy and exergy analysis has indicated that the proposed stand-alone solar thermal system offers an effective way to sustainable energy production in hot and dry climates.

Fundamental Considerations for Designing Compact Solar Thermal Power and Ejector Cooling Systems in Hot Climates

2013 ◽  
Author(s):  
TieJun Zhang ◽  
Saleh Mohamed ◽  
Guanqiu Li
Keyword(s):  
Low Cost ◽  
Thermal Power ◽  
Density Ratio ◽  
Cooling Capacity ◽  
Solar Thermal ◽  
Working Fluid ◽  
Absolute Pressure ◽  
Low Grade ◽  
Alternative Refrigerants ◽  
Promising Alternative

A combined thermal power and ejector refrigeration cooling cycle is proposed in this paper to harness low-grade solar energy. It utilizes abundant and low-cost hydrocarbon as the working fluid. Hydrocarbon has been identified as a promising alternative to existing high global-warming-potential refrigerants (i.e., HFC refrigerant R134a) in next-generation refrigeration systems. Several typical alternative refrigerants are evaluated by considering their fundamental thermophysical properties: absolute pressure level, volumetric cooling capacity, surface tension, saturated liquid/vapor density ratio and kinematic viscosity. Comparing with R1234yf, R1234ze and R744 (CO2), hydrocarbon refrigerants, such as R290 (propane) and R601 (pentane), do have inherent advantages for either cooling or power generation purposes in hot climates: lower flow resistance and better heat transfer at higher temperature. Fundamental phase stability and transition issues have been considered in designing pentane vapor ejectors for combined power and cooling cycles operating at high ambient temperature. Thermodynamic analysis has indicated that the proposed solar thermal system can provide an effective way to sustainable energy production in hot and dry climates.

Maximization of Exergy Gain in High Temperature Solar Thermal Receivers by Choice of Pipe Radius

1991 ◽  
Vol 113 (2) ◽  
pp. 337-340 ◽  
Author(s):  
P. Bannister
Keyword(s):  
Power Systems ◽  
Thermal Power ◽  
Solar Thermal ◽  
Working Fluid ◽  
Pumping Power ◽  
Design Values ◽  
Parabolic Dish ◽  
Solar Thermal Collectors ◽  
Pipe Radius ◽  
Typical Design

The problem of optimizing the radius of boiler tubes in a radiation-dominated environment such as a solar thermal power receiver is examined. The trade-off between heat transfer and pumping power is investigated, resulting in an explicit expression for the radius that maximizes the net exergy gain under turbulent flow conditions. The effect of the pumping power being generated on site is included, thus making the result particularly applicable to the design of stand-alone power systems. Examples using typical design values for small parabolic dish solar thermal collectors using water and steam as the working fluid are given to illustrate the characteristics of the problem.

scholarly journals Dynamic Modeling and Preliminary Performance Analysis of a New Solar Thermal Reverse Osmosis Desalination Process

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 4015 ◽  
Author(s):  
Clément Lacroix ◽  
Maxime Perier-Muzet ◽  
Driss Stitou
Keyword(s):  
Energy Consumption ◽  
Reverse Osmosis ◽  
Dynamic Modeling ◽  
Thermal Energy ◽  
Thermal Power ◽  
Solar Thermal ◽  
Working Fluid ◽  
Small Scale ◽  
Low Grade ◽  
Solar Collectors

Reverse osmosis (RO) is a desalination technique that is commonly preferred because of its low energy consumption. In this paper, an innovative, thermally powered RO desalination process is presented. This new thermo-hydraulic process uses solar thermal energy in order to realize the pressurization of the saltwater beyond its osmotic pressure to allow its desalination. This pressurization is enabled thanks to a piston or a membrane set in motion in a reservoir by a working fluid that follows a thermodynamic cycle similar to an Organic Rankine Cycle. In this cycle, the evaporator is heated by low-grade heat, such as the one delivered by flat-plate solar collectors, while the condenser is cooled by the saltwater to be treated. Such an installation, designed for small-scale (1 to 10 m3·day−1) brackish water desalination, should enable an average daily production of 500 L of drinkable water per m² of solar collectors with a specific thermal energy consumption of about 6 kWhth·m−3. A dynamic modeling of the whole process has been developed in order to study its dynamic cyclic operating behavior under variable solar thermal power, to optimize its design, and to maximize its performances. This paper presents the preliminary performance results of such a solar-driven desalination process.

Supercritical Carbon Dioxide Brayton Cycles Driven by Solar Thermal Power Tower System

2015 ◽  
Vol 1116 ◽  
pp. 94-129 ◽  
Author(s):  
Maimoon Atif ◽  
Fahad A. Al-Sulaiman
Keyword(s):  
Carbon Dioxide ◽  
Mathematical Model ◽  
Power Systems ◽  
Solar Power ◽  
Current Model ◽  
Thermal Power ◽  
Solar Thermal ◽  
Solar Thermal Power ◽  
Thermal Energy Storage Systems ◽  
Tower System

This chapter starts with a background about concentrating solar power systems and thermal energy storage systems and then a detailed literature review about concentrated solar power systems and supercritical Brayton carbon dioxide cycles. Next, a mathematical model was developed and presented which generates and optimizes a heliostat field effectively. This model was developed to demonstrate the optimization of a heliostat field using differential evolution, which is an evolutionary algorithm. The current model illustrates how to employ the developed model and its advantages. The optimization process calculates the optical performance parameters at every step of the optimization considering all the heliostats; thus yields accurate results as discussed in this chapter. On the other hand, complete mathematical model of supercritical CO2Brayton cycles when integrated with solar thermal power tower system was presented and discussed.

1-D Model Analysis of Tesla Turbine for Small Scale Organic Rankine Cycle (ORC) System

2017 ◽  
Author(s):  
Jian Song ◽  
Chun-wei Gu
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Organic Rankine Cycle ◽  
Axial Flow ◽  
Rankine Cycle ◽  
Expansion Ratio ◽  
Working Fluid ◽  
Small Scale ◽  
Low Grade ◽  
D Model

Energy shortage and environmental deterioration are two crucial issues that the developing world has to face. In order to solve these problems, conversion of low grade energy is attracting broad attention. Among all of the existing technologies, Organic Rankine Cycle (ORC) has been proven to be one of the most effective methods for the utilization of low grade heat sources. Turbine is a key component in ORC system and it plays an important role in system performance. Traditional turbine expanders, the axial flow turbine and the radial inflow turbine are typically selected in large scale ORC systems. However, in small and micro scale systems, traditional turbine expanders are not suitable due to large flow loss and high rotation speed. In this case, Tesla turbine allows a low-cost and reliable design for the organic expander that could be an attractive option for small scale ORC systems. A 1-D model of Tesla turbine is presented in this paper, which mainly focuses on the flow characteristics and the momentum transfer. This study improves the 1-D model, taking the nozzle limit expansion ratio into consideration, which is related to the installation angle of the nozzle and the specific heat ratio of the working fluid. The improved model is used to analyze Tesla turbine performance and predict turbine efficiency. Thermodynamic analysis is conducted for a small scale ORC system. The simulation results reveal that the ORC system can generate a considerable net power output. Therefore, Tesla turbine can be regarded as a potential choice to be applied in small scale ORC systems.

scholarly journals Evolution and feasibility of decentralized concentrating solar thermal power systems for modern energy access in rural areas

2016 ◽  
Vol 3 ◽  
Author(s):  
Amy Mueller ◽  
Matthew Orosz ◽  
Arun Kumar Narasimhan ◽  
Rajeev Kamal ◽  
Harold F. Hemond ◽  
...  
Keyword(s):  
Power Systems ◽  
Rural Areas ◽  
Thermal Power ◽  
Solar Thermal ◽  
Energy Access ◽  
Solar Thermal Power ◽  
Image Position

ABSTRACT

Comparative Optimization on the Focusing Methods of Solar-Electric Dish Stirling System

2012 ◽  
Vol 236-237 ◽  
pp. 714-719
Author(s):  
Wei Lan ◽  
Bin Wang ◽  
Yi Ming Feng
Keyword(s):  
Power Systems ◽  
High Speed ◽  
Power Plants ◽  
Solar Power ◽  
Thermal Power ◽  
Engineering Application ◽  
Solar Thermal ◽  
Solar Thermal Power ◽  
Low Emission ◽  
Practical Engineering

Nowadays, the high-speed economic development has caused significant consumption of energy. While the circumstance is getting severer, solar energy is taken as a kind of clean, environmental friendly resource with infinite storage that has aroused a wide public concern. Photovoltaic and solar thermal are two main categories of solar applications. Because of its high conversion efficiency, low emission and flexible installation, dish Stirling solar power technology is more preferable to be used among the solar thermal area. From the view of practical engineering application, this paper illustrates multiple focusing methods of the current dish Stirling solar power systems in detail, and the comparison of these methods are given to analyze their advantages, disadvantages and their application scenarios. It can be used for the future development of dish Stirling solar power technology and applied as a reference for large dish solar thermal power plants’ installations and tests.

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