Effect of Hygienic Design and Operational Parameters on Frosting and Defrosting of Evaporators in Refrigerated Food Processing and Storage Facilities

2015 ◽  
pp. 660-719
Author(s):  
Frank Theo Moerman ◽  
Kostadin Fikiin
Keyword(s):  
Heat Transfer ◽  
Low Temperature ◽  
Temperature Regime ◽  
Extensive Literature ◽  
Operational Parameters ◽  
Heat Transfer Efficiency ◽  
And Performance ◽  
Processing And Storage ◽  
And Storage

Proper control and performance of evaporators in food refrigeration facilities are vital to provide a suitable temperature regime, safety, quality and wholesomeness of refrigerated products at minimum electricity costs. When humid air passes along the surfaces of a low-temperature evaporator, frost is usually formed, which decreases the heat transfer efficiency. Frosting and defrosting phenomena have been extensively investigated for different industrial scenarios and extensive literature exists in the matter. However, no studies have been published so far to address in a comprehensive way the methods and patterns of evaporator defrosting as affected by hygienic design implications and criteria. This book chapter is intended to fill in this gap by enforcing hygienic imperatives in the evaporator design. Various design solutions and conditions of operation are considered as decisive in determining the amount, thickness and structure of the frost build-up. Advantages and drawbacks of diverse defrost methods are outlined with regards to contamination risks in refrigeration facilities.

scholarly journals Distributed Data Collection for the Next Generation ATLAS EventIndex Project

2019 ◽  
Vol 214 ◽  
pp. 04010
Author(s):  
Álvaro Fernández Casaní ◽  
Dario Barberis ◽  
Javier Sánchez ◽  
Carlos García Montoro ◽  
Santiago González de la Hoz ◽  
...  
Keyword(s):  
Data Collection ◽  
Current Approach ◽  
Distributed Data ◽  
Future Data ◽  
Data Files ◽  
Complete Catalogue ◽  
And Performance ◽  
Processing And Storage ◽  
Storage Technologies ◽  
And Storage

The ATLAS EventIndex currently runs in production in order to build a complete catalogue of events for experiments with large amounts of data. The current approach is to index all final produced data files at CERN Tier0, and at hundreds of grid sites, with a distributed data collection architecture using Object Stores to temporarily maintain the conveyed information, with references to them sent with a Messaging System. The final backend of all the indexed data is a central Hadoop infrastructure at CERN; an Oracle relational database is used for faster access to a subset of this information. In the future of ATLAS, instead of files, the event should be the atomic information unit for metadata, in order to accommodate future data processing and storage technologies. Files will no longer be static quantities, possibly dynamically aggregating data, and also allowing event-level granularity processing in heavily parallel computing environments. It also simplifies the handling of loss and or extension of data. In this sense the EventIndex may evolve towards a generalized whiteboard, with the ability to build collections and virtual datasets for end users. This proceedings describes the current Distributed Data Collection Architecture of the ATLAS EventIndex project, with details of the Producer, Consumer and Supervisor entities, and the protocol and information temporarily stored in the ObjectStore. It also shows the data flow rates and performance achieved since the new Object Store as temporary store approach was put in production in July 2017. We review the challenges imposed by the expected increasing rates that will reach 35 billion new real events per year in Run 3, and 100 billion new real events per year in Run 4. For simulated events the numbers are even higher, with 100 billion events/year in run 3, and 300 billion events/year in run 4. We also outline the challenges we face in order to accommodate future use cases in the EventIndex.

scholarly journals Numerical Simulation and Design of a High-Temperature, High-Pressure Fluid Transport Pipe

2020 ◽  
Vol 10 (17) ◽  
pp. 5890
Author(s):  
Jiyoung Yoon ◽  
Junkyu Park ◽  
Jinhyoung Park
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
High Pressure ◽  
High Temperature ◽  
Low Temperature ◽  
Fluid Transport ◽  
Projectile Velocity ◽  
Gas Leakage ◽  
And Performance ◽  
High Temperature High Pressure

When designing a hand caliber with a high-temperature, high-pressure internal fluid transport pipe, reliability, safe use, and performance must be considered. Reliability refers to the stress caused by thermo-mechanical load; safe use refers to the low-temperature burns that might occur upon contact, and high-temperature burns caused by gas leakage occurring in the cylinder gap; and performance refers to projectile velocity. In this study, numerical simulation methods for heat transfer, structure analysis, and gas leakage are proposed so that solutions can be designed to account for the above three criteria. Furthermore, a hand-caliber design guide is presented. For heat transfer and structural analysis, mesh size, the transient convective heat transfer coefficient, and boundary conditions are described. Regarding gas leakage, methods reflecting projectile motion and determination of the molecular weight of the propellant are described. As a result, a designed hand caliber will have a high reliability, because the thermo-mechanical stress is lower than the yield stress. There will be little risk of low-temperature burns, but there will be a high temperature-burn risk, owing to gas leakage in the cylinder gap. The larger the cylinder-gap size, the greater the gas leakage and the smaller projectile velocity. The presented numerical simulation method can be applied to evaluate various aspects of other structures that require high-temperature, high-pressure fluid-transport pipes.

scholarly journals Kaolin, bentonite, and zeolites as feed supplements for animals: health advantages and risks

2012 ◽  
Vol 49 (No. 10) ◽  
pp. 389-399 ◽  
Author(s):  
M. Trckova ◽  
L. Matlova ◽  
L. Dvorska ◽  
I. Pavlik
Keyword(s):  
Animal Species ◽  
Potential Toxicity ◽  
Diarrheal Diseases ◽  
Positive Effects ◽  
Advantages And Disadvantages ◽  
Feed Supplements ◽  
And Performance ◽  
Processing And Storage ◽  
Potential Interactions ◽  
And Storage

Feeding kaolin as a supplement to pigs for prevention of diarrheal diseases has been introduced into some farms in the CzechRepublic. Peat was used in the 1990s for a similar purpose; however, most farmers ceased feeding peat as a supplement because of its frequent contamination with conditionally pathogenic mycobacteria, esp. with Mycobacterium avium subsp. hominissuis. The aim of the present paper is to review available literature from the standpoint of the advantages and disadvantages related to feeding kaolin as a supplement to animals. Its positive effects exerted through the diet primarily consist in its adsorbent capability which may be useful for detoxification of the organism and for prevention of diarrheal diseases in pigs. Because the mechanism of action of kaolin fed as a supplement is unknown, a risk related to its potential interactions with other nutrient compounds of the diet exists. Therefore, it is necessary to investigate the effectiveness and safety of feeding kaolin in detail with regard to the health status and performance of each farm animal species. The disadvantage of kaolin use is its potential toxicity, provided it has been mined from the environment with natural or anthropogenic occurrence of toxic compounds. Another risk factor is a potential contamination of originally sterile kaolin with conditionally pathogenic mycobacteria from surface water, dust, soil, and other constituents of the environment in the mines during kaolin extraction, processing and storage.

CFD Modeling of Flow and Heat Transfer Inside a Liquid-Cooled Exhaust Manifold

2003 ◽  
Author(s):  
Rade Milanovic ◽  
Chenn Q. Zhou ◽  
Jim Majdak ◽  
Robert Cantwell
Keyword(s):  
Heat Transfer ◽  
Flow Property ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Cfd Modeling ◽  
Inlet Temperature ◽  
Operational Parameters ◽  
Manifold Optimization ◽  
Parametric Effects ◽  
And Performance

Liquid cooled exhaust manifolds are used in turbo charged diesel and gas engines in the marine and various industrial applications. Performance of the manifold has a significant impact on the engine efficiency. Modifying manifold design and changing operational parameters are ways to improve its performance. With the rapid advance of computer technology and numerical methods, Computational Fluid Dynamics (CFD) has become a powerful tool that can provide useful information for manifold optimization. In this study, commercial CFD software (FLUENT®) was used to analyze liquid cooled exhaust manifolds. Detailed information of flow property distribution and heat transfer were obtained in order to provide a fundamental understanding of the manifold operation. Experimental data was compared with the CFD results to validate the numerical simulation. Computations were performed to investigate the parametric effects of operating conditions (engine rotational speed, coolant flow rate, coolant inlet temperature, exhaust gas inlet temperature, surface roughness of the manifold’s material) on the performance of the manifold. Results were consistent with the experimental observations. Suggestions were made to improve the manifold design and performance.

scholarly journals Capturing and querying fine-grained provenance of preprocessing pipelines in data science

2020 ◽  
Vol 14 (4) ◽  
pp. 507-520
Author(s):  
Adriane Chapman ◽  
Paolo Missier ◽  
Giulia Simonelli ◽  
Riccardo Torlone
Keyword(s):  
Predictive Models ◽  
Data Science ◽  
Data Preparation ◽  
Fine Grained ◽  
Storage Overhead ◽  
Core Set ◽  
And Performance ◽  
Definition Of ◽  
Processing And Storage ◽  
And Storage

Data processing pipelines that are designed to clean, transform and alter data in preparation for learning predictive models, have an impact on those models' accuracy and performance, as well on other properties, such as model fairness. It is therefore important to provide developers with the means to gain an in-depth understanding of how the pipeline steps affect the data, from the raw input to training sets ready to be used for learning. While other efforts track creation and changes of pipelines of relational operators, in this work we analyze the typical operations of data preparation within a machine learning process, and provide infrastructure for generating very granular provenance records from it, at the level of individual elements within a dataset. Our contributions include: (i) the formal definition of a core set of preprocessing operators, and the definition of provenance patterns for each of them, and (ii) a prototype implementation of an application-level provenance capture library that works alongside Python. We report on provenance processing and storage overhead and scalability experiments, carried out over both real ML benchmark pipelines and over TCP-DI, and show how the resulting provenance can be used to answer a suite of provenance benchmark queries that underpin some of the developers' debugging questions, as expressed on the Data Science Stack Exchange.

Ground Moisture Condensation around the GSHP Borehole

2014 ◽  
Vol 664 ◽  
pp. 236-242 ◽  
Author(s):  
G.P. Vasilyev ◽  
N.V. Peskov ◽  
M.M. Brodach ◽  
V.A. Lichman ◽  
A.N. Dmitriev ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Systems Design ◽  
Numerical Data ◽  
Theoretical Research ◽  
Ministry Of Education ◽  
Substantial Impact ◽  
Heat Transfer Efficiency ◽  
Moisture Condensation ◽  
And Performance ◽  
Transfer Properties

Presented in this article are the results of theoretical research carried out with financial support from the Ministry of Education and Science of the Russian Federation (contract ID RFMEFI57914X0026) and demonstrating the need to consider the changes in ground heat transfer properties in geothermal borehole heat modeling, due to moisture condensation/evaporation in the ground pores. It is our opinion that in GSHP systems design, the quantity of the boreholes is often overestimated and the associated parameters oversized while the extent of the ground heat transfer is underestimated. In most cases, in designing GSHP operation and performance, this is due to the incorrect assessment of the ground moisture content, which has a most tangible effect on the ground heat transfer properties. This article demonstrates the need to consider the ground moisture condensation/evaporation in GSHP systems design. Presented in the article is the mathematical simulation of the ground pore moisture condensation at the GSHP boreholes. Also presented is numerical data derived from the calculations to assess the effect of the ground pore moisture condensation on the borehole heat transfer efficiency. Through analysis and experimentation, it was determined that the ground pore moisture condensation have a substantial impact on the GSHP efficiency.

scholarly journals Cooling System for Primary Low Temperature Processing and Storage of Grains of Small Frachioned

2017 ◽  
Vol 53 (5) ◽  
pp. 52-58
Author(s):  
S. Petushenko
Keyword(s):  
Comparative Analysis ◽  
Low Temperature ◽  
Energy Conservation ◽  
Cooling System ◽  
Commonwealth Of Independent States ◽  
Low Temperature Processing ◽  
The World ◽  
Independent States ◽  
Processing And Storage ◽  
And Storage

The analysis of different aspects of grain refrigeration on elevators of Ukraine, Commonwealth of Independent States (CIS)   and in the world is carried out. The advantage of the refrigeration method is shown  concerning the quality  and   of energy conservation. A comparative analysis of various types of refrigeration machines operating on ozone-friendly refrigerants has been carried out. It is shown that it is more profitable to use heat that is worked out from refrigerating machines.

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