Design Considerations of Small Solar Collector Systems Using Plane Heliostats

1979 ◽  
Author(s):  
K. J. Waldron ◽  
Kambiz Kheyrandish ◽  
A. C. Meyers
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Industrial Process ◽  
Working Fluid ◽  
Optical Simulation ◽  
Receiver Design ◽  
Design Studies ◽  
Heating And Cooling ◽  
Central Receiver ◽  
Primary Advantage

The primary advantage of the central receiver concept is the minimization of heat transmission in the form of enthalpy of a working fluid. This is replaced by efficient and low cost optical energy transmission. This characteristic renders collectors using heliostats to reflect solar radiation onto a stationary receiver attractive for small to medium scale, as well as large scale collection. This paper describes several years of design studies and simulations of central receiver systems scaled to be suitable for heating and cooling of commercial buildings or for some industrial process heat applications. The relatively small distances between the heliostats and receiver, vertical flat plate receiver geometry, and relatively low receiver result in optical simulation characteristics of such systems quite different to those of the large solar tower systems. The variation in radiation intensity over the surface of the receiver due to the relatively irregular shape of the insolated patch from a heliostat segment, and due to dispersion produced by off axis aberration in segmented heliostats, requires several unique features in the receiver design.

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 Large-Scale Pumped Thermal Electricity Storages—Converting Energy Using Shallow Lined Rock Caverns, Carbon Dioxide and Underground Pumped-Hydro

2019 ◽  
Vol 9 (19) ◽  
pp. 4150 ◽  
Author(s):  
Pascal Lalanne ◽  
Paul Byrne
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
District Heating ◽  
Energy Transition ◽  
Heating And Cooling ◽  
Long Duration ◽  
Low Emission ◽  
Rock Cavern ◽  
Lined Rock Cavern ◽  
Thermal Stores

A fast-paced energy transition needs a higher penetration of renewables, of heating and cooling in the worldwide energy mix. With three novelties 1-of using shallow high-pressure LRC (Lined Rock Cavern) excavated close to storage needs, 2-of using a slow-moving CO2 piston applying steady pressure on the hydro part of UPHES (Underground Pumped Hydro Energy Storage) and 3-of relying on inexpensive thermal stores for long-duration storage, CO2 UPHES coupled with PTES (Pumped Thermal Electricity Storage) could become, at expected Capex cost of only 20 USD/kWh electrical, a game-changer by allowing the complete integration of intermittent renewable sources. Moreover, even though this early conceptual work requires validation by simulation and experimentation, CO2 UPHES as well as UPHES-PTES hybrid storage could also allow a low-cost and low-emission integration of intermittent renewables with future district heating and cooling networks.

scholarly journals A FLUID FLOW ANALYSIS OF A JET EJECTOR SYSTEM USED IN INDUSTRIAL APPLICATIONS

2020 ◽  
Vol 26 (3) ◽  
pp. 143-147
Author(s):  
IONEL OLARU
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Flow Analysis ◽  
Industrial Applications ◽  
Coefficient Of Performance ◽  
Working Fluid ◽  
Widespread Application ◽  
Ejector System ◽  
Fluid Flow Analysis ◽  
Conventional Systems

Many studies have been conducted for jet ejectors used in the recovery of solar energy or for their use in refrigeration systems for various industrial applications. Generally, these types of ejectors are using water as the working fluid because water have a low cost, a chemical stability and is safe to use. Naturally, other refrigerants, with large-scale application for industry, can be used. In such a type of jet ejector, besides selection of the refrigerant, the design of ejector is very important, with strongly influence to the performance, because the compression ratio depends on the geometry of the nozzle and on the geometry of the diffuser. Compared to other refrigeration systems, those with ejector have some advantages: simplicity in construction, high liability and low cost. However, it has a coefficient of performance lower than conventional systems, this limited the widespread application of ejector refrigeration systems.

Development and Testing of a Low-Cost Rapid-Cycle Hot Embossing System for Manufacturing Microscale Parts

2009 ◽  
Author(s):  
Melinda Hale ◽  
David E. Hardt
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Polymeric Materials ◽  
Hot Embossing ◽  
Capital Cost ◽  
Electrical Heating ◽  
Cycle Times ◽  
Capital Costs ◽  
Heating And Cooling ◽  
Order Of Magnitude

Hot embossing is an effective technology for replicating micro-scale features in polymeric materials, but large-scale adoption of this method is hindered by high capital costs and longer cycle times relative to other technologies. This paper details a hot embossing machine design strategy motivated by maximum production speed with minimal capital cost. Innovative design aspects include the choice of new ceramic substrate heaters for electrical heating, design of a moveable heat sink to minimize heat load during the heating cycle, and the careful design of the thermal elements to minimize the heating and cooling cycle times. The hot embossing equipment fabricated from this design has a capital cost estimated to be an order of magnitude less than currently available options. The minimum cycle time is two minutes, and microstructures are replicated within a maximum area of 25mm by 75mm. The hot embossing machine has been tested to characterize the process variability. Runs of polymethylmethacrylate (PMMA) parts manufactured using this equipment are measured to have submicron variation under a variety of processing conditions.

Utilization of Expansion Work in Transcritical CO2 Heat Pumps in Combined Heating and Cooling

2008 ◽  
Author(s):  
Nikola Stosic ◽  
Ian K. Smith
Keyword(s):  
Control Strategies ◽  
Industrial Process ◽  
Power Input ◽  
Heat Pumps ◽  
Operating Conditions ◽  
Hot Water ◽  
Design Parameters ◽  
Working Fluid ◽  
Heating And Cooling ◽  
Twin Screw

The use of CO2 as a refrigerant in transcritical vapour compression cycles has significant advantages, for systems which require simultaneous heating and cooling at approximately equal rates. However, then need for a compressor, to operate across high pressure differences, and the large throttle losses associated with these pressure differences have limited its use. This paper describes a study carried out to evaluate the efficiency gains and cost benefits possible from such a system when a twin screw machine is used to both compress and expand the working fluid in a single unit. It also shows the values of the critical design parameters required to optimise the system’s potential advantages when used in larger combined heating and cooling systems in industrial process and heat generation plants. The results show that recovery of work from the expansion process improves the COP by 15 to 20%. For the design conditions specified in this paper, this implies that the expander is worth fitting if it can be installed for a cost of less than approximately €750/kW of shaft power input. Thus, depending on the operating conditions, transcritical CO2 heat pumps using a compressor-expander can produce hot water at 90°C with a COP of approximately 6, with thermal outputs of up to 1.5 MW. This could be extended with simple control strategies up to outputs of 10 MW.

An Assessment of a Low-Cost Wastewater Disposal System after Twenty-Five Years of Operation

1987 ◽  
Vol 19 (5-6) ◽  
pp. 701-710 ◽  
Author(s):  
B. L. Reidy ◽  
G. W. Samson
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Wastewater Disposal ◽  
Industrial Base ◽  
Industrial Wastewaters ◽  
The Past ◽  
Gasification Process ◽  
Appropriate Treatment ◽  
Environmentally Safe ◽  
Coal Resource

A low-cost wastewater disposal system was commissioned in 1959 to treat domestic and industrial wastewaters generated in the Latrobe River valley in the province of Gippsland, within the State of Victoria, Australia (Figure 1). The Latrobe Valley is the centre for large-scale generation of electricity and for the production of pulp and paper. In addition other industries have utilized the brown coal resource of the region e.g. gasification process and char production. Consequently, industrial wastewaters have been dominant in the disposal system for the past twenty-five years. The mixed industrial-domestic wastewaters were to be transported some eighty kilometres to be treated and disposed of by irrigation to land. Several important lessons have been learnt during twenty-five years of operating this system. Firstly the composition of the mixed waste stream has varied significantly with the passage of time and the development of the industrial base in the Valley, so that what was appropriate treatment in 1959 is not necessarily acceptable in 1985. Secondly the magnitude of adverse environmental impacts engendered by this low-cost disposal procedure was not imagined when the proposal was implemented. As a consequence, clean-up procedures which could remedy the adverse effects of twenty-five years of impact are likely to be costly. The question then may be asked - when the total costs including rehabilitation are considered, is there really a low-cost solution for environmentally safe disposal of complex wastewater streams?

Causes of gear pump fails and methods for their elimination

2020 ◽  
pp. 98-107
Author(s):  
Vitaliy A. Zuyevskiy ◽  
Daniil O. Klimyuk ◽  
Ivan A. Shemberev
Keyword(s):  
Adhesion Strength ◽  
Production Systems ◽  
Low Cost ◽  
High Strength ◽  
Strength Properties ◽  
Research Purpose ◽  
Working Fluid ◽  
Gear Pump ◽  
Repair Service ◽  
Recovery Method

Gear pumps are an important element of many production systems and their replacement in case of failure can be quite expensive, so it is important to have a modern and well-tuned technology for their recovery. There are many methods for restoring the pump's performance, depending on the reason that led to its failure. (Research purpose) The research purpose is in determining what causes most often lead to loss of pump performance, and developing a recovery method that provides the greatest post-repair service life of the pump and low cost of repair. (Materials and methods) Authors took into account that the applied coatings must have sufficient adhesion strength and resistance to mechanical, thermal and corrosion loads during operation. It was found that most often significant leaks of the working fluid, leading to failure, occur due to an increase in the gap between the inner surface of the housing and the gears due to active wear of the housing wells. Authors determined that the method of electric spark treatment of worn-out housing wells is best suited to perform the task (a large post-repair resource and low costs). (Results and discussion) It was found by laboratory studies of the adhesion strength of electric spark coatings with various electrodes that the best transfer of the material to the substrate is provided by bronze electrodes BrMKts3-1. It was noted that the coatings applied using the BrMKts3-1 electrode have high strength properties. (Conclusions) Research conducted in the center for collective use "Nano-Center" VIM confirmed the possibility of effective recovery of the gear pump by electric spark treatment.

scholarly journals Rapid, large-scale species discovery in hyperdiverse taxa using 1D MinION sequencing

BMC Biology ◽  
2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Amrita Srivathsan ◽  
Emily Hartop ◽  
Jayanthi Puniamoorthy ◽  
Wan Ting Lee ◽  
Sujatha Narayanan Kutty ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Large Scale ◽  
Low Cost ◽  
Small Body ◽  
Small Subset ◽  
Similar Species ◽  
Large Species ◽  
Morphological Examination ◽  
Species Discovery ◽  
Short Period

Abstract Background More than 80% of all animal species remain unknown to science. Most of these species live in the tropics and belong to animal taxa that combine small body size with high specimen abundance and large species richness. For such clades, using morphology for species discovery is slow because large numbers of specimens must be sorted based on detailed microscopic investigations. Fortunately, species discovery could be greatly accelerated if DNA sequences could be used for sorting specimens to species. Morphological verification of such “molecular operational taxonomic units” (mOTUs) could then be based on dissection of a small subset of specimens. However, this approach requires cost-effective and low-tech DNA barcoding techniques because well-equipped, well-funded molecular laboratories are not readily available in many biodiverse countries. Results We here document how MinION sequencing can be used for large-scale species discovery in a specimen- and species-rich taxon like the hyperdiverse fly family Phoridae (Diptera). We sequenced 7059 specimens collected in a single Malaise trap in Kibale National Park, Uganda, over the short period of 8 weeks. We discovered > 650 species which exceeds the number of phorid species currently described for the entire Afrotropical region. The barcodes were obtained using an improved low-cost MinION pipeline that increased the barcoding capacity sevenfold from 500 to 3500 barcodes per flowcell. This was achieved by adopting 1D sequencing, resequencing weak amplicons on a used flowcell, and improving demultiplexing. Comparison with Illumina data revealed that the MinION barcodes were very accurate (99.99% accuracy, 0.46% Ns) and thus yielded very similar species units (match ratio 0.991). Morphological examination of 100 mOTUs also confirmed good congruence with morphology (93% of mOTUs; > 99% of specimens) and revealed that 90% of the putative species belong to the neglected, megadiverse genus Megaselia. We demonstrate for one Megaselia species how the molecular data can guide the description of a new species (Megaselia sepsioides sp. nov.). Conclusions We document that one field site in Africa can be home to an estimated 1000 species of phorids and speculate that the Afrotropical diversity could exceed 200,000 species. We furthermore conclude that low-cost MinION sequencers are very suitable for reliable, rapid, and large-scale species discovery in hyperdiverse taxa. MinION sequencing could quickly reveal the extent of the unknown diversity and is especially suitable for biodiverse countries with limited access to capital-intensive sequencing facilities.

scholarly journals Accelerated Randomized Methods for Receiver Design in Extra-Large Scale MIMO Arrays

2021 ◽  
pp. 1-1
Author(s):  
Victor Croisfelt Rodrigues ◽  
Abolfazl Amiri ◽  
Taufik Abrao ◽  
Elisabeth De Carvalho ◽  
Petar Popovski
Keyword(s):  
Large Scale ◽  
Receiver Design ◽  
Randomized Methods ◽  
Mimo Arrays
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