Performance analysis of a novel cascade vapor compression system for small-scale desalination and cooling

2021 ◽  
pp. 1-40
Author(s):  
Yousif Alkhulaifi ◽  
Jihad Hassan Hussain Al-Sadah ◽  
Esmail M. A. Mokheimer
Keyword(s):  
Cooling System ◽  
Cost Savings ◽  
Small Scale ◽  
Evaporator Temperature ◽  
Simultaneous Generation ◽  
Performance Improvements ◽  
Multiple Parameters ◽  
Significant Performance ◽  
Innovative System ◽  
Cascade Refrigeration

Abstract The demand for improving living standards has led to increasing freshwater consumption and comfort cooling, requiring significant performance improvements. In this regard, a novel and efficient cascade refrigeration system for simultaneous generation of considerable freshwater and cooling amounts is proposed. The system does not require dedicated components for desalinating seawater because they are dual-purpose. Utilizing the cascade configuration enhances energy efficiency by lowering the compression work while improving energy recovery by utilizing existing heat to vaporize seawater for desalination. A mathematical model of the innovative system based on thermodynamic and economic principles has been developed and utilized to predict the proposed system's thermal performance and cost savings. A comprehensive analysis has been conducted to study the effect of multiple parameters such as the evaporator, condenser, and brine boiling temperatures. The main studied parameters were COP, GOR, freshwater production, and total cost savings. For a 10 TR unit, the freshwater production was between 56.11 – 73.36 kg/h, with cost savings reaching 2,226 US$/yr. It was found that the freshwater production increased with condenser and brine boiling temperature but decreased with evaporator temperature. The COP improvement can be as much as 26% over the reference cooling system without desalination.

The Future of Plasma-Based Surface Engineering Techniques in Tribology (Keynote)

2005 ◽  
Author(s):  
Allan Matthews ◽  
Adrian Leyland
Keyword(s):  
Surface Engineering ◽  
Performance Enhancement ◽  
Bulk Material ◽  
Cost Savings ◽  
Cost Effective ◽  
Ceramic Coatings ◽  
Performance Improvements ◽  
Treatment Techniques ◽  
Wide Range ◽  
Macro Scale

Over the past twenty years or so, there have been major steps forward both in the understanding of tribological mechanisms and in the development of new coating and treatment techniques to better “engineer” surfaces to achieve reductions in wear and friction. Particularly in the coatings tribology field, improved techniques and theories which enable us to study and understand the mechanisms occurring at the “nano”, “micro” and “macro” scale have allowed considerable progress to be made in (for example) understanding contact mechanisms and the influence of “third bodies” [1–5]. Over the same period, we have seen the emergence of the discipline which we now call “Surface Engineering”, by which, ideally, a bulk material (the ‘substrate’) and a coating are combined in a way that provides a cost-effective performance enhancement of which neither would be capable without the presence of the other. It is probably fair to say that the emergence and recognition of Surface Engineering as a field in its own right has been driven largely by the availability of “plasma”-based coating and treatment processes, which can provide surface properties which were previously unachievable. In particular, plasma-assisted (PA) physical vapour deposition (PVD) techniques, allowing wear-resistant ceramic thin films such as titanium nitride (TiN) to be deposited on a wide range of industrial tooling, gave a step-change in industrial productivity and manufactured product quality, and caught the attention of engineers due to the remarkable cost savings and performance improvements obtained. Subsequently, so-called 2nd- and 3rd-generation ceramic coatings (with multilayered or nanocomposite structures) have recently been developed [6–9], to further extend tool performance — the objective typically being to increase coating hardness further, or extend hardness capabilities to higher temperatures.

scholarly journals An Attention-Based Multilayer GRU Model for Multistep-Ahead Short-Term Load Forecasting

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1639
Author(s):  
Seungmin Jung ◽  
Jihoon Moon ◽  
Sungwoo Park ◽  
Eenjun Hwang
Keyword(s):  
Power Consumption ◽  
Prediction Models ◽  
Short Term Memory ◽  
Load Forecasting ◽  
Input Sequence ◽  
Short Term ◽  
Performance Improvements ◽  
Short Term Load Forecasting ◽  
Significant Performance ◽  
Input Variables

Recently, multistep-ahead prediction has attracted much attention in electric load forecasting because it can deal with sudden changes in power consumption caused by various events such as fire and heat wave for a day from the present time. On the other hand, recurrent neural networks (RNNs), including long short-term memory and gated recurrent unit (GRU) networks, can reflect the previous point well to predict the current point. Due to this property, they have been widely used for multistep-ahead prediction. The GRU model is simple and easy to implement; however, its prediction performance is limited because it considers all input variables equally. In this paper, we propose a short-term load forecasting model using an attention based GRU to focus more on the crucial variables and demonstrate that this can achieve significant performance improvements, especially when the input sequence of RNN is long. Through extensive experiments, we show that the proposed model outperforms other recent multistep-ahead prediction models in the building-level power consumption forecasting.

scholarly journals Infection Preventionist Run Clostridioides difficile Testing Diagnostic Stewardship Protocol- Experience From a Rural Community Hospital

2020 ◽  
Vol 41 (S1) ◽  
pp. s484-s485
Author(s):  
Raghavendra Tirupathi ◽  
Ruth Freshman ◽  
Norma J Montoy ◽  
Melissa Gross
Keyword(s):  
Cost Savings ◽  
Antibiotic Use ◽  
First Year ◽  
Multiple Parameters ◽  
Clostridioides Difficile ◽  
Stewardship Program ◽  
Commercial Company ◽  
Surgical History ◽  
Test Ordering ◽  
Infection Preventionists

Background: Distinguishing active Clostridioides difficile infection (CDI) from asymptomatic colonization remains a challenging task in the era of PCR testing. Inappropriate testing leads to overtesting and overdiagnosis, inadvertent treatment, and isolation in addition to laboratory identified (LabID) events, leading to increased incidence to hospital-onset CDI (HO-CDI). The institution has a nurse-driven C. difficile test ordering protocol, and we noted a significant increase in the HO-CDI incidence in 2017 due to inappropriate testing, with rates as high as 0.94 per 1,000 patient days. Methods: In September 2017, a multidisciplinary team reviewed and initiated algorithm-based testing with mandatory audit and review by infection preventionists (IPs) under the guidance of an ID physician of all ordered tests. They reviewed the adequacy and legitimacy of order for multiple parameters, including minimum 3 loose stools in 24 hours, use of laxatives in last 24 hours, consistency of the sample, presence of at least 1 clinical parameters (ie, fever, abdominal pain, leukocytosis, sepsis, or septic shock), recent or concomitant antibiotic use, recent PCR testing in the last 14 days, and chart review for medical and/or surgical history. The IPs served as the gatekeepers to testing and rejected the samples that were deemed inappropriate. Ambiguous cases were discussed with the ID specialist. On the microscope lab side, all specimens sent were batched to be run twice a day at 8:30 a.m. and 2:30 p.m., and testing was performed only on the samples cleared by infection preventionists. Results: The number of PCR tests completed in the comparison quarter of 2016 was 220, which decreased to 157 tests in 2017 with a reduction of 28%. After a full year of implementation of the diagnostic stewardship protocol, the number of completed PCR tests decreased to 626 from 940 PCR tests in 2016, with an overall 34% decrease in testing. In the year following the implementation of diagnostic stewardship, HO-CDI decreased from 60 events in 2017 to 43 events in 2018, with a reduction of 28%. Subsequently, HO-CDI further decreased in 2019 from 43 to 28, with a reduction of 35%. Since the implementation of the project in 2017, HO-CDIs have decreased by 54% overall. The reduction in 314 C. difficile PCR tests in the first year led to a savings of $8,300 in laboratory testing supplies. The reduction of HO CDI by 17 led to cost avoidance of $293,420. Conclusions: Our experience shows that the IP-run diagnostic stewardship program was highly successful in streamlining testing, with cost savings on several fronts.Funding: NoneDisclosures: NoneDisclosures:Commercial Company : If I am presenting research funded by a commercial company, the information presented will be based on generally accepted scientific principals and methods, and will not promote the commercial interest of the funding company.DisagreeRaghavendra Tirupathi

scholarly journals Development and Evaluation of an Ultrasonic Humidifier to Control Humidity in a Cold Storage Room for Postharvest Quality Management of Dates

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 949
Author(s):  
Maged Mohammed ◽  
Nashi Alqahtani ◽  
Hamadttu El-Shafie
Keyword(s):  
Quality Management ◽  
Cold Storage ◽  
Cooling System ◽  
Positive Impact ◽  
Droplet Diameter ◽  
Postharvest Quality ◽  
Main Element ◽  
Small Scale ◽  
Storage Room ◽  
Ultrasonic Humidifier

Dates are subjected to postharvest losses in quality and quantity caused by water loss, fermentation, insect infestation, and microbial spoilage during storage. Cold storage is the main element in the postharvest quality management used for fruit preservation. Although cold storage is used for dates, precision control of the relative humidity (RH) using ultrasonic applications is not used thus far, or it is applied to other fruits on a small scale. Therefore, we designed and constructed an ultrasonic humidifier (DUH) for RH control in the cold storage room (CSR) of dates. The optimum air velocity of 3 m s−1 at the outlets of the DUH ducts produced a mist amount of 6.8 kg h-1 with an average droplet diameter of 4.26 ± 1.43 µm at the applied voltage of 48 V and frequency of 2600 kHz of the transducers. The experimental validation was carried out by comparing a CSR controlled with the DUH with two conventional CSRs. The three tested CSRs were similar in dimensions, cooling system, and amount of stored dates. The time required for cooling 800 kg of dates in the controlled CSR from 25 °C to the target temperature of 5 °C was approximately 48 h. The DUH precisely controlled the RH at the maximum RH set point of 80% in the tested CSR at 5 °C. The controlled RH at 80% has a positive impact on the physicochemical characteristics of the stored dates. It significantly reduced the weight loss of the fruits and preserved fruit mass, moisture content, water activity, firmness, and color parameters. However, no significant effect was observed on fruit dimensions, sphericity, and aspect ratio. The microbial loads of mesophilic aerobic bacteria, molds, and yeasts fell within the acceptable limits in all tested CSRs. Both stored date fruits and artificially infested dates showed no signs of insect activity in the controlled CSR at the temperature of 5 °C and RH of 80%. The DUH proved to be a promising technology for postharvest quality management for dates during cold storage.

scholarly journals Data Downlink System in the Vast IOT Node Condition Assisted by UAV, Large Intelligent Surface, and Power and Data Beacon

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5748
Author(s):  
Zhibo Zhang ◽  
Qing Chang ◽  
Na Zhao ◽  
Chen Li ◽  
Tianrun Li
Keyword(s):  
Communication Systems ◽  
Optimization Problems ◽  
Minimum Energy ◽  
Numerical Algorithms ◽  
Flight Trajectory ◽  
Performance Improvements ◽  
Minimum Energy Consumption ◽  
Significant Performance ◽  
Downlink System ◽  
The Internet Of Things

The future development of communication systems will create a great demand for the internet of things (IOT), where the overall control of all IOT nodes will become an important problem. Considering the essential issues of miniaturization and energy conservation, in this study, a new data downlink system is designed in which all IOT nodes harvest energy first and then receive data. To avoid the unsolvable problem of pre-locating all positions of vast IOT nodes, a device called the power and data beacon (PDB) is proposed. This acts as a relay station for energy and data. In addition, we model future scenes in which a communication system is assisted by unmanned aerial vehicles (UAVs), large intelligent surfaces (LISs), and PDBs. In this paper, we propose and solve the problem of determining the optimal flight trajectory to reach the minimum energy consumption or minimum time consumption. Four future feasible scenes are analyzed and then the optimization problems are solved based on numerical algorithms. Simulation results show that there are significant performance improvements in energy/time with the deployment of LISs and reasonable UAV trajectory planning.

VESTA 3for three-dimensional visualization of crystal, volumetric and morphology data

2011 ◽  
Vol 44 (6) ◽  
pp. 1272-1276 ◽  
Author(s):  
Koichi Momma ◽  
Fujio Izumi
Keyword(s):  
Search Algorithm ◽  
Voronoi Tessellation ◽  
Three Dimensional ◽  
Structure Parameters ◽  
Volumetric Data ◽  
Complex Molecules ◽  
Visualization System ◽  
Performance Improvements ◽  
Significant Performance

VESTAis a three-dimensional visualization system for crystallographic studies and electronic state calculations. It has been upgraded to the latest version,VESTA 3, implementing new features including drawing the external morphology of crystals; superimposing multiple structural models, volumetric data and crystal faces; calculation of electron and nuclear densities from structure parameters; calculation of Patterson functions from structure parameters or volumetric data; integration of electron and nuclear densities by Voronoi tessellation; visualization of isosurfaces with multiple levels; determination of the best plane for selected atoms; an extended bond-search algorithm to enable more sophisticated searches in complex molecules and cage-like structures; undo and redo in graphical user interface operations; and significant performance improvements in rendering isosurfaces and calculating slices.

Fräsen partikelverstärkter Titanmatrix-Verbundwerkstoffe*/Milling of particle-reinforced titanium metal matrix composites

2017 ◽  
Vol 107 (04) ◽  
pp. 301-305
Author(s):  
E. Prof. Uhlmann ◽  
F. Kaulfersch
Keyword(s):  
High Performance ◽  
High Wear Resistance ◽  
Tool Geometry ◽  
Matrix Composites ◽  
Titanium Matrix ◽  
Titanium Matrix Composites ◽  
Performance Improvements ◽  
Significant Performance ◽  
High Temperature Components ◽  
Process Strategy

Partikelverstärkte Titanmatrix-Verbundwerkstoffe erlauben erhebliche Leistungssteigerungen im Bereich hochtemperaturbeanspruchter Struktur- und Funktionsbauteile. Die durch die Partikelverstärkung gesteigerte Verschleißbeständigkeit, Festigkeit und Härte bedeuten eine große Herausforderung an die spanende Bearbeitung derartiger Hochleistungswerkstoffe. Mittels Zerspanuntersuchungen beim Fräsen konnten unter Variation der Werkzeuggeometrie, der Schneidstoffe und der Prozessstrategie Parameterbeiche identifiziert werden, mit denen die prozesssichere Zerspanung partikelverstärkter Titanmatrix-Verbundwerkstoffe möglich ist.   Particle-reinforced titanium matrix composites ensure significant performance improvements of structural and functional high-temperature components. However, the high wear resistance, toughness and hardness due to particle reinforcement is a major challenge in machining these high performance materials. By conducting milling experiments with a variation of tool geometry, cutting material and process strategy, process parameters could be identified that enable efficient machining of particle-reinforced titanium matrix composites.

Preliminary Evaluation of the 24 Ft. Diameter Fan Performance In the MinWaterCSP Large Cooling Systems Test Facility

2021 ◽  
Author(s):  
S. J. van der Spuy ◽  
D. N. J. Els ◽  
L. Tieghi ◽  
G. Delibra ◽  
A. Corsini ◽  
...  
Keyword(s):  
Scaling Laws ◽  
Static Pressure ◽  
Cooling System ◽  
Pressure Rise ◽  
Full Scale ◽  
Test Facility ◽  
Small Scale ◽  
Preliminary Evaluation ◽  
Cfd Analysis ◽  
Setting Angle

Abstract The MinWaterCSP project was defined with the aim of reducing the cooling system water consumption and auxiliary power consumption of concentrating solar power (CSP) plants. A full-scale, 24 ft (7.315 m) diameter model of the M-fan was subsequently installed in the Min WaterCSP cooling system test facility, located at Stellenbosch University. The test facility was equipped with an in-line torque arm and speed transducer to measure the power transferred to the fan rotor, as well as a set of rotating vane anemometers upstream of the fan rotor to measure the air volume flow rate passing through the fan. The measured results were compared to those obtained on the 1.542 m diameter ISO 5801 test facility using the fan scaling laws. The comparison showed that the fan power values correlated within +/− 7% to those of the small-scale fan, but at a 1° higher blade setting angle for the full-scale fan. To correlate the expected fan static pressure rise, a CFD analysis of the 24 ft (7.315 m) diameter fan installation was performed. The predicted fan static pressure rise values from the CFD analysis were compared to those measured on the 1.542 m ISO test facility, for the same fan. The simulation made use of an actuator disc model to represent the effect of the fan. The results showed that the predicted results for fan static pressure rise of the installed 24 ft (7.315 m) diameter fan correlated closely (smaller than 1% difference) to those of the 1.542 m diameter fan at its design flowrate but, once again, at approximately 1° higher blade setting angle.

Superalloy Cooling System for the Composite Rim of an Inside-Out Ceramic Turbine

2017 ◽  
Author(s):  
N. Courtois ◽  
F. Ebacher ◽  
P. K. Dubois ◽  
N. Kochrad ◽  
C. Landry ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Cooling System ◽  
High Strength ◽  
Carbon Composite ◽  
Flow Rate Ratio ◽  
Small Scale ◽  
Inlet Temperature ◽  
Operating Temperatures ◽  
Critical Components ◽  
Inside Out

The use of ceramics in gas turbines potentially allows for very high cycle efficiency and power density, by increasing operating temperatures. This is especially relevant for sub-megawatt gas turbines, where the integration of complex blade cooling greatly affects machine capital cost. However, ceramics are brittle and prone to fragile, catastrophic failure, making their current use limited to static and low-stress parts. Using the inside-out ceramic turbine (ICT) configuration solves this issue by converting the centrifugal blade loading to compressive stress, by using an external high-strength carbon-polymer composite rim. This paper presents a superalloy cooling system designed to protect the composite rim and allow it to withstand operating temperatures up to 1600 K. The cooling system was designed using one-dimensional (1D) models, developed to predict flow conditions as well as the temperatures of its critical components. These models were subsequently supported with computational fluid dynamics and used to conduct a power scalability study on a single stage ICT. Results suggest that the ICT configuration should achieve a turbine inlet temperature (TIT) of 1600 K with a composite rim cooling-to-main mass flow rate ratio under 5.2% for power levels above 350 kW. A proof of concept was performed by experimental validation of a small-scale 15 kW prototype, using a commercially available bismaleimide-carbon (BMI-carbon) composite rim and Inconel® 718 nickel-based alloy. The combination of numerical and experimental results show that the ICT can operate at a TIT of 1100 K without damage to the composite rim.

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