The document experimentally investigates enhancing the performance of a domestic refrigerator by adding a shell and tube heat exchanger after the condenser. Ammonia is used as the cooling fluid in the heat exchanger to further subcool the refrigerant. Testing showed the coefficient of performance increased 18.4% with the additional heat exchanger due to increased refrigeration effect and lower operating pressures and temperatures. Graphs compare the heat rejection, refrigeration effect, power input, and COP between the original and modified systems.
Heat Recovery System in Domestic RefrigeratorIjrdt Journal
Refrigeration is a process in which work is done to move heat from one location to another. Refrigeration technology has rapidly evolved in last century from ice harvesting to temperature controlled rail cars. Most widely used current application of refrigeration is for air-conditioning of homes and public buildings. During refrigeration, heat from the refrigerant is dissipated for the successful completion of a refrigeration cycle. In normal household refrigerators, the heat from the refrigerant is removed using a condenser where the refrigerant cools and the air surrounding the condenser heats up. The strategy of how to recover the dissipated heat to develop a waste heat recovery system is relevant. The energy lost in waste heat cannot be fully recovered. However, much of the heat can be recovered and the loss can be minimized by adopting different measures. Hot air can be used for space heating, industrial drying, preheating aspirated air for oil burners, or any other application requiring warm air. The purpose of this project is to demonstrate the technical feasibility of a heat recovery system to recover waste heat from the condenser in the refrigerator and to reuse it for heating application.
Design and Fabrication of Vapour Absorption Refrigeration System [Libr-H20]IJMER
Most of the energies are utilized by the industries due to depletion of fossil fuels and
increasing the fuel price to exploit the maximum presented energy from the waste heat source. The
industry which utilizes steam turbine exhaust carries a considerable amount of thermal energy. This
energy can be set in to positive use as a heat source for vapour absorption system to serves as cooling
system. This paper illustrates the thermal and fiscal advantages of using single effect lithium bromide
water absorption by means of waste heat. The objective of this work is to hypothetical design of lithium
bromide water absorption Refrigeration system using waste heat from any industry steam turbine
exhaust
Heat Recovery System in Domestic RefrigeratorIjrdt Journal
Refrigeration is a process in which work is done to move heat from one location to another. Refrigeration technology has rapidly evolved in last century from ice harvesting to temperature controlled rail cars. Most widely used current application of refrigeration is for air-conditioning of homes and public buildings. During refrigeration, heat from the refrigerant is dissipated for the successful completion of a refrigeration cycle. In normal household refrigerators, the heat from the refrigerant is removed using a condenser where the refrigerant cools and the air surrounding the condenser heats up. The strategy of how to recover the dissipated heat to develop a waste heat recovery system is relevant. The energy lost in waste heat cannot be fully recovered. However, much of the heat can be recovered and the loss can be minimized by adopting different measures. Hot air can be used for space heating, industrial drying, preheating aspirated air for oil burners, or any other application requiring warm air. The purpose of this project is to demonstrate the technical feasibility of a heat recovery system to recover waste heat from the condenser in the refrigerator and to reuse it for heating application.
Design and Fabrication of Vapour Absorption Refrigeration System [Libr-H20]IJMER
Most of the energies are utilized by the industries due to depletion of fossil fuels and
increasing the fuel price to exploit the maximum presented energy from the waste heat source. The
industry which utilizes steam turbine exhaust carries a considerable amount of thermal energy. This
energy can be set in to positive use as a heat source for vapour absorption system to serves as cooling
system. This paper illustrates the thermal and fiscal advantages of using single effect lithium bromide
water absorption by means of waste heat. The objective of this work is to hypothetical design of lithium
bromide water absorption Refrigeration system using waste heat from any industry steam turbine
exhaust
Design &Analysis of Waste Heat Recovery System for Domestic RefrigeratorIJMER
Heat is energy, so energy saving is one of the key matters from view point of fuel consumption
and for the protection of global environment. So it is necessary that a significant and concrete effort should
be made for conserving energy through waste heat recovery too. The main objective of this paper is to study
“Waste Heat recovery system for domestic refrigerator”. An attempt has been made to utilize waste heat
from condenser of refrigerator. This heat can be used for number of domestic and industrial purposes. In
minimum constructional, maintenance and running cost, this system is much useful for domestic purpose. It
is valuable alternative approach to improve overall efficiency and reuse the waste heat. The study has
shown that such a system is technically feasible and economically viable.
WASTE HEAT RECOVERY IN DOMESTIC REFRIGERATION SYSTEM IN THE APPLICATION OF WA...Journal For Research
Heat is the energy, so energy saving is one of the key matters for the protection of global environment. Heat also radiated from our domestic refrigerator. This waste heat from refrigerator will affect the environmental because as heat in the environment will increases it will cause global warming. So it is necessary that a significant effort should be made for conserving energy through waste heat recovery too. So An attempt has been made to utilize waste heat from condenser of refrigerator. This heat can be used for various of domestic and industrial purposes. In minimum constructional, maintenance and running cost, this system is very useful for domestic purpose. It is valuable alternative approach to increase overall efficiency and reuse the waste heat. The study has shown that such a system is technically feasible and economical. This system is a cabin that we are going to install over the head of the simple refrigerator, this cabin will be an arrangement of coils that will work as a heat exchanger for reuse of waste heat. These coils are hot coils of condenser of the refrigerator that will be modified and will put in the cabin. It can serve the purpose of cooking, geysers etc. Besides, the refrigerator may be used as conventional refrigerator. Further COP will also increase. Heat rejection may occur directly to the air in the case of a conventional household domestic refrigerator having air-cooled condenser. This system rejected less heat to the environment so it is safer in environmental aspects also.
EFFECT OF CONCENTRATION OF LITHIUM BROMIDE MIXTURE ON COP FOR SINGLE EFFECT L...Editor IJMTER
In this paper effect of concentration of lithium bromide mixture on Co-efficient of
performance (COP) for single effect LiBr-H2O absorption chillers is calculated. Then find out how
the cop varies with the concentration of lithium bromide. For finding cop temperature of condenser
varies and the other parameter (temperature of generator, temperature of absorber, capacity of
evaporator, temperature of evaporator temperature of absorber) remains constant. Optimal value of
COP obtained 0.65 varying temperature of condenser.
Reheating Refrigeration System to control and utilize the rejected heat from an air conditioner to reduce the input power of the compressor without affecting the cooling effect.
Experimental Investigation of a Household Refrigerator Using Evaporative-Cool...inventy
The objective of this paper was to investigate experimentally the effect of Evaporative-cooled condenser in a household refrigerator. The experiment was done using HCF134a as the refrigerant. The performance of the household refrigerator with air-cooled and Evaporative-cooled condenser was compared for different load conditions. The results indicate that the refrigerator performance had improved when evaporative-cooled condenser was used instead of air-cooled condenser on all load conditions. Evaporativecooled condenser reduced the energy consumption when compared with the air-cooled condenser. There was also an enhancement in coefficient of performance (COP) when evaporative-cooled condenser was used instead of air-cooled condenser. The Evaporative cooled heat exchanger was designed and the system was modified by retrofitting it, instead of the conventional air-cooled condenser by making drop wise condensation using water and forced circulation over the condenser. From the experimental analysis it is observed that the COP of evaporative cooled system increased by 13.44% compared to that of air cooled system. So the overall efficiency and refrigerating effect is increased. In minimum constructional, maintenance and running cost, the system is much useful for domestic purpose. This study also revealed that combining a evaporative cooled system along with conventional water cooled system under the condition that the defrost water obtained from the freezer is used for drop wise condensation over condenser and water cooled condensation of the condenser at the bottom using remaining defrost water would reduce the power consumption, work done and hence further increase in refrigerating effect of the system. The study has shown that such a system is technically feasible and economically viable
It is the Short Description of the Vapor Absorption Cooling/ Refrigeration System.Contains Intro, Comparison of VCCS 7 VACS, Diagram, Advantages & Disadvantages & Applications of the System
Effectiveness analysis of a thermo siphon charged with norflurane as a runnin...eSAT Journals
Abstract This work presents an investigation of the thermal performance on Thermo-siphon charged with norflurane as a running fluid,
with electro chemical nano coating. This analysis was carried out to scrutinize the optimized fill ratio and angle of inclination for
better heat transfer enhancement. The fluctuation of heat transfer ability of the thermo-siphon was analyzed for the input heat
transfer rate varies from 0 to 350 W for various filling ratios and inclination of angle. The various fill ratio of the refrigerant used
in the analysis are 70%, 60%, 50%, 40% and 30% and angle of inclination for carrying out orientation analysis were taken as 0°,
45° and 90°. Experimental results showed that the fill ratio and orientation analysis showed a better heat transfer performance on
thermo-siphon while using Norflurane as a working fluid. Experimental investigations and calculations depicted that the thermal
resistance of 50% fill ratio was found to be lower than that of other fill ratios thereby leading to a better thermal performance for
thermo-siphon charged with Norflurane. Further, upon further investigation for orientation analysis it was found that the
horizontal inclination provided better heat transfer. Hence this present investigation indicates that the thermal performance of a
thermo-siphon can be enhanced using Norflurane at an optimal fill ratio of 50% and at an angle of inclination of 0°.
Keywords: Angle of Inclination, Filling Ratio, Heat Transfer, Norflurane, Thermal Resistance,Thermo-Siphon,
Electro Chemical Nano Coating.
Design &Analysis of Waste Heat Recovery System for Domestic RefrigeratorIJMER
Heat is energy, so energy saving is one of the key matters from view point of fuel consumption
and for the protection of global environment. So it is necessary that a significant and concrete effort should
be made for conserving energy through waste heat recovery too. The main objective of this paper is to study
“Waste Heat recovery system for domestic refrigerator”. An attempt has been made to utilize waste heat
from condenser of refrigerator. This heat can be used for number of domestic and industrial purposes. In
minimum constructional, maintenance and running cost, this system is much useful for domestic purpose. It
is valuable alternative approach to improve overall efficiency and reuse the waste heat. The study has
shown that such a system is technically feasible and economically viable.
WASTE HEAT RECOVERY IN DOMESTIC REFRIGERATION SYSTEM IN THE APPLICATION OF WA...Journal For Research
Heat is the energy, so energy saving is one of the key matters for the protection of global environment. Heat also radiated from our domestic refrigerator. This waste heat from refrigerator will affect the environmental because as heat in the environment will increases it will cause global warming. So it is necessary that a significant effort should be made for conserving energy through waste heat recovery too. So An attempt has been made to utilize waste heat from condenser of refrigerator. This heat can be used for various of domestic and industrial purposes. In minimum constructional, maintenance and running cost, this system is very useful for domestic purpose. It is valuable alternative approach to increase overall efficiency and reuse the waste heat. The study has shown that such a system is technically feasible and economical. This system is a cabin that we are going to install over the head of the simple refrigerator, this cabin will be an arrangement of coils that will work as a heat exchanger for reuse of waste heat. These coils are hot coils of condenser of the refrigerator that will be modified and will put in the cabin. It can serve the purpose of cooking, geysers etc. Besides, the refrigerator may be used as conventional refrigerator. Further COP will also increase. Heat rejection may occur directly to the air in the case of a conventional household domestic refrigerator having air-cooled condenser. This system rejected less heat to the environment so it is safer in environmental aspects also.
EFFECT OF CONCENTRATION OF LITHIUM BROMIDE MIXTURE ON COP FOR SINGLE EFFECT L...Editor IJMTER
In this paper effect of concentration of lithium bromide mixture on Co-efficient of
performance (COP) for single effect LiBr-H2O absorption chillers is calculated. Then find out how
the cop varies with the concentration of lithium bromide. For finding cop temperature of condenser
varies and the other parameter (temperature of generator, temperature of absorber, capacity of
evaporator, temperature of evaporator temperature of absorber) remains constant. Optimal value of
COP obtained 0.65 varying temperature of condenser.
Reheating Refrigeration System to control and utilize the rejected heat from an air conditioner to reduce the input power of the compressor without affecting the cooling effect.
Experimental Investigation of a Household Refrigerator Using Evaporative-Cool...inventy
The objective of this paper was to investigate experimentally the effect of Evaporative-cooled condenser in a household refrigerator. The experiment was done using HCF134a as the refrigerant. The performance of the household refrigerator with air-cooled and Evaporative-cooled condenser was compared for different load conditions. The results indicate that the refrigerator performance had improved when evaporative-cooled condenser was used instead of air-cooled condenser on all load conditions. Evaporativecooled condenser reduced the energy consumption when compared with the air-cooled condenser. There was also an enhancement in coefficient of performance (COP) when evaporative-cooled condenser was used instead of air-cooled condenser. The Evaporative cooled heat exchanger was designed and the system was modified by retrofitting it, instead of the conventional air-cooled condenser by making drop wise condensation using water and forced circulation over the condenser. From the experimental analysis it is observed that the COP of evaporative cooled system increased by 13.44% compared to that of air cooled system. So the overall efficiency and refrigerating effect is increased. In minimum constructional, maintenance and running cost, the system is much useful for domestic purpose. This study also revealed that combining a evaporative cooled system along with conventional water cooled system under the condition that the defrost water obtained from the freezer is used for drop wise condensation over condenser and water cooled condensation of the condenser at the bottom using remaining defrost water would reduce the power consumption, work done and hence further increase in refrigerating effect of the system. The study has shown that such a system is technically feasible and economically viable
It is the Short Description of the Vapor Absorption Cooling/ Refrigeration System.Contains Intro, Comparison of VCCS 7 VACS, Diagram, Advantages & Disadvantages & Applications of the System
Effectiveness analysis of a thermo siphon charged with norflurane as a runnin...eSAT Journals
Abstract This work presents an investigation of the thermal performance on Thermo-siphon charged with norflurane as a running fluid,
with electro chemical nano coating. This analysis was carried out to scrutinize the optimized fill ratio and angle of inclination for
better heat transfer enhancement. The fluctuation of heat transfer ability of the thermo-siphon was analyzed for the input heat
transfer rate varies from 0 to 350 W for various filling ratios and inclination of angle. The various fill ratio of the refrigerant used
in the analysis are 70%, 60%, 50%, 40% and 30% and angle of inclination for carrying out orientation analysis were taken as 0°,
45° and 90°. Experimental results showed that the fill ratio and orientation analysis showed a better heat transfer performance on
thermo-siphon while using Norflurane as a working fluid. Experimental investigations and calculations depicted that the thermal
resistance of 50% fill ratio was found to be lower than that of other fill ratios thereby leading to a better thermal performance for
thermo-siphon charged with Norflurane. Further, upon further investigation for orientation analysis it was found that the
horizontal inclination provided better heat transfer. Hence this present investigation indicates that the thermal performance of a
thermo-siphon can be enhanced using Norflurane at an optimal fill ratio of 50% and at an angle of inclination of 0°.
Keywords: Angle of Inclination, Filling Ratio, Heat Transfer, Norflurane, Thermal Resistance,Thermo-Siphon,
Electro Chemical Nano Coating.
IOSR Journal of Humanities and Social Science is an International Journal edited by International Organization of Scientific Research (IOSR).The Journal provides a common forum where all aspects of humanities and social sciences are presented. IOSR-JHSS publishes original papers, review papers, conceptual framework, analytical and simulation models, case studies, empirical research, technical notes etc.
Multiple Equilibria and Chemical Distribution of Some Bio Metals With β-Amide...IOSR Journals
Abstract: Solution Chemistry of some bivalent metal ions (viz. CoII , NiII ,CuII ,ZnII ) with β-amide α-aminosuccinate (Asparagine)/ α-aminoisoverate( Valine ) (A) and 5-methyl 2,4- dioxopyrimidine ( Thymine ) (B)ligands have been analyzed. Formation constant of quaternary metal complexes and complexation equilibria at 30±1ºC and at constant ionic strength (I=0.1M NaNO3 ) have been explored potentiometrically. Formation of quaternary species in addition to hydroxyl, protonated, binary and ternary species have been reported. Overall formation constant have been evaluated using SCOGS computer program.Species distribution curves of complexes have been plotted as a function of pH to visualize the equlibria system and was refined using ORIGIN program.The metal ligand formation constant of MA,MB,MAB and M1M2AB type of complexes follow Irving William order. The order of stability constants of quaternary systems have been observed as: Cu – Ni > Cu –Zn > Cu–Co > Ni – Zn > Ni – Co > Co –Zn. Solution structures of metal complexes with said ligands have been compared and discussed.
an experiment on a co2 air conditioning system with copper heat exchangersINFOGAIN PUBLICATION
This paper presented an experiment on a CO2 air conditioning system with copper heat exchangers. In this study, the compressor and cooler were tested with hydraulic method to determine the deformed and torn temperatures. The results show that conventional compressor is not suitable for using high pressure, due to the COP of cycle is very low (0.5 only). With CO2 compressor, the cycle can be achieved COP of 3.07 at the evaporative temperature of 10C. This value equals with COP of commercial air conditioning system presently.
Low charge ammonia vapour compression refrigeration system for residential ai...RAJESHKUMAR4616
Ammonia is widely used as a refrigerant in industrial systems for food refrigeration, distribution warehousing and process cooling. It has more recently been proposed for use in applications such as water chilling for air-conditioning systems but has not yet received widespread acceptance for this application. This project was envisaged to develop an ammonia vapour compression refrigeration system of 3 TR capacity for residential air conditioning and to analyze the minimum possible charge in order to reduce leakage hazards associated with the system. This would increase the use of ammonia in a more efficient way. It has Zero ODP and GWP which makes it to be environment friendly. Even though Ammonia is a cost effective and energy efficient alternative to conventional refrigerants like HCFCs and HFCs, etc., it is toxic. So, toxicity of ammonia needs to be addressed. This calls for low inventory of refrigerant in individual system. The present work aims at reducing the specific charge of ammonia for residential air conditioning system with air cooled condenser.
It will help to the students of Mechanical Engineering. These notes are according to HVAC Subject. Some important topics are here for your good understanding. These are written in easy language, u can understand easily.
ENERGY AUDIT presentationin power system .pptxReshevSharma
An energy audit is a systematic process of evaluating and analyzing energy usage in a building, facility, or industrial process to identify opportunities for energy efficiency improvements, cost savings, and environmental sustainability. The goal of an energy audit is to assess energy consumption patterns, identify areas of inefficiency or waste, and recommend measures to optimize energy usage and reduce overall energy consumption.
Here's an overview of the typical steps involved in conducting an energy audit:
1. **Pre-Audit Planning:**
Define the scope and objectives of the energy audit, including the areas or systems to be evaluated, the level of detail required, and the desired outcomes. Identify key stakeholders, establish audit goals, and gather relevant documentation, such as utility bills, building plans, and equipment specifications.
2. **Data Collection and Analysis:**
Collect comprehensive data on energy consumption, including utility bills, meter readings, and operational data
This paper describes an experimental study of using the waste heat from a Panasonic Under-
Ceiling split room air - conditioner had a rated capacity of 3.51 kW (12,000 Btu/h). An under – ceiling
split type air conditioning for heating domestic water in private homes. Energy recovery improved the
performance, and the recovered energy could replace electricity completely for heating domestic water
use. An extra charge of refrigerant in the air-conditioner could prevent its compressor from over heating
during energy recovery. The experimental conducted on varies capacity of the range from 22.5 litres to
120 litres storage tank. Results show the water temperature increased lies in the range of 50 OC to 65
OC. It was found that, when the initial water temperature in the 22.5 litres storage tank 27 OC, the water
temperature reached 65 OC in 105 minutes. For 120 litres water, temperature increased from 27 OC to 62
OC,5 in 240 minutes.
Flue gas low temperature heat recovery system for air conditioningeSAT Journals
Abstract Huge amount of energy wasted through the flue gas in thermal power station causes great concern in recent years. Discharging hot flue gas in the environment is not only a wastage of energy but also increases the rate of global warming. Efforts are given world -wide to harness the energy for useful purposes. In this work, the waste heat of flue gas in a 350 MW thermal power plant is utilized in vapor absorption air conditioning plant. Gas to liquid multi-pass cross flow heat exchanger that have been placed in the existing space between boiler and chimney. The dimensions of the finally selected heat exchanger are 0.106m × 2.4m × 3.4m. The number of pipes required for the heat exchanger is found to be 12 using iteration method and temperature of water at the outlet of last pipe is 101.1℃. The extracted energy from the flue gas is used to heat water to be utilized in the generator of a vapor absorption refrigeration system that has produced a refrigerating capacity of 70 TR. approximately. Due to the corrosive nature of flue gas, heat recovery is confined up to the acid dew point temperature of the flue gas. Suitable software is used to find out the detailed design parameters of Gas to liquid multi-pass cross flow heat exchangers. Out of many feasible designs of heat exchangers, the most economic design is selected as the final design. Keywords—Air Conditioning; Flue Gas; Heat Exchanger; Heat Recovery; Vapour Absorption Machine
PHP Frameworks: I want to break free (IPC Berlin 2024)Ralf Eggert
In this presentation, we examine the challenges and limitations of relying too heavily on PHP frameworks in web development. We discuss the history of PHP and its frameworks to understand how this dependence has evolved. The focus will be on providing concrete tips and strategies to reduce reliance on these frameworks, based on real-world examples and practical considerations. The goal is to equip developers with the skills and knowledge to create more flexible and future-proof web applications. We'll explore the importance of maintaining autonomy in a rapidly changing tech landscape and how to make informed decisions in PHP development.
This talk is aimed at encouraging a more independent approach to using PHP frameworks, moving towards a more flexible and future-proof approach to PHP development.
Generative AI Deep Dive: Advancing from Proof of Concept to ProductionAggregage
Join Maher Hanafi, VP of Engineering at Betterworks, in this new session where he'll share a practical framework to transform Gen AI prototypes into impactful products! He'll delve into the complexities of data collection and management, model selection and optimization, and ensuring security, scalability, and responsible use.
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
A tale of scale & speed: How the US Navy is enabling software delivery from l...sonjaschweigert1
Rapid and secure feature delivery is a goal across every application team and every branch of the DoD. The Navy’s DevSecOps platform, Party Barge, has achieved:
- Reduction in onboarding time from 5 weeks to 1 day
- Improved developer experience and productivity through actionable findings and reduction of false positives
- Maintenance of superior security standards and inherent policy enforcement with Authorization to Operate (ATO)
Development teams can ship efficiently and ensure applications are cyber ready for Navy Authorizing Officials (AOs). In this webinar, Sigma Defense and Anchore will give attendees a look behind the scenes and demo secure pipeline automation and security artifacts that speed up application ATO and time to production.
We will cover:
- How to remove silos in DevSecOps
- How to build efficient development pipeline roles and component templates
- How to deliver security artifacts that matter for ATO’s (SBOMs, vulnerability reports, and policy evidence)
- How to streamline operations with automated policy checks on container images
SAP Sapphire 2024 - ASUG301 building better apps with SAP Fiori.pdfPeter Spielvogel
Building better applications for business users with SAP Fiori.
• What is SAP Fiori and why it matters to you
• How a better user experience drives measurable business benefits
• How to get started with SAP Fiori today
• How SAP Fiori elements accelerates application development
• How SAP Build Code includes SAP Fiori tools and other generative artificial intelligence capabilities
• How SAP Fiori paves the way for using AI in SAP apps
The Art of the Pitch: WordPress Relationships and SalesLaura Byrne
Clients don’t know what they don’t know. What web solutions are right for them? How does WordPress come into the picture? How do you make sure you understand scope and timeline? What do you do if sometime changes?
All these questions and more will be explored as we talk about matching clients’ needs with what your agency offers without pulling teeth or pulling your hair out. Practical tips, and strategies for successful relationship building that leads to closing the deal.
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
Encryption in Microsoft 365 - ExpertsLive Netherlands 2024Albert Hoitingh
In this session I delve into the encryption technology used in Microsoft 365 and Microsoft Purview. Including the concepts of Customer Key and Double Key Encryption.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
1. IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE)
e-ISSN: 2278-1684,p-ISSN: 2320-334X, Volume 12, Issue 2 Ver. V (Mar - Apr. 2015), PP 63-67
www.iosrjournals.org
DOI: 10.9790/1684-12256367 www.iosrjournals.org 63 | Page
Experimental Investigation on Domestic Refrigerator by Shell
and Tube Heat Exchanger after the Condenser Using Sub Colling
of Refregaring Fluid
E Saidulu*
, G.S.Guru Dattatreya**
*
Asst.prof, Mechanical Engineering Department, Siddhartha institute of technology & sciences ,Ghatkesar,
Hyderabad, India,
**
Asst. prof, Mechanical Engineering Department, Siddhartha institute of technology & sciences, Ghatkesar,
Hyderabad, India,
Abstract: Majority of refrigerator works on vapor compression refrigeration system. The system consists of
compressor, condenser, expansion valve and evaporator. The performance of the system depends on the
performance of all components of the system. The main objective of the present study is to study the
performance of a domestic refrigerator by placing shell and tube type heat exchanger immediately after the
condenser to extract more amount of heat by sub cooling process by using ammonia as an external cooling
media.
Keywords: Sub cooling, Ammonia, Shell and tube heat exchanger, Coefficient of performance.
I. Introduction:
The term sub cooling refers to a liquid existing at a temperature below its normal saturation
temperature. The sub cooling technology not only provides for additional capacity but also can reduce
compressor power leading to higher overall system efficiency besides saving energy. The strategic placement of
sub cooler for cooling in the liquid zone allow the operating pressure and temperature of the refrigerator system
to be reduced and the refrigerant in the system to provide the highest cooling effect in the evaporator.
Fig. 1.1 vapor compression refrigeration system
Sub cooling desirable, reasons: It increases the efficiency of the system since the amount of heat being
removed per kilogram of refrigerant circulated is greater. In other words we pump fewer refrigerants through the
system to maintain the refrigerated temperature you want. This reduces the amount of time that the compressor
must run to maintain the temperature.
Sub cooling is beneficial because it prevents the liquid refrigerant from changing to a gas before it gets
to the Evaporator. Pressure drops in the liquid piping and the vertical risers can reduce refrigerant pressure to the
point where it will boil or flash in the liquid line. The change of phase causes the refrigerant to absorb heat
before it reaches the evaporator. Inadequate sub cooling prevents the expansion valve from properly metering
liquid refrigerant in to the evaporator, resulting in poor system performance.
Selection of tube material:
The tube material plays an important role in the design of refrigeration and air conditioning system.
The tube material should have good thermal conductivity, as heat is transferred from hot to a cold side through
the tubes, there is a temperature difference. Because of the tendency of the tube material the material is
2. Experimental Investigation on Domestic Refrigerator by Shell and Tube Heat Exchanger after …
DOI: 10.9790/1684-12256367 www.iosrjournals.org 64 | Page
thermally expands differently at various temperatures, and also thermal stresses will also occur during operation.
All of these requirements call for careful selection of strong, thermally conductive, corrosion resistant, high
quality tube material, typically metals including copper alloy, stainless steel, galvanized iron, carbon steel,
nickel etc. Poor choice of tube material could result in a leak through the tube between shell and tube sides
causing fluid cross-contamination and possibly loss of pressure.
Fig.1.2: Shell and tube heat exchanger
Shell and tube heat exchanger:
A shell and tube heat exchanger is a class of heat exchanger designs. It is the most common type of
heat exchanger and is suited for high pressure applications. As its name implies, this type of the heat exchanger
consists of a shell with bundle of tubes inside it. One fluid runs through the tubes, another fluid flows over the
tubes to transfer heat between the two fluids. The set of tubes is called tube bundle, and may be composed of
Several types of tubes.
107.80
Properties of ammonia:
Molecular formula NH3 Molar mass 17.031 g/mol Appearance Colorless gas Odour strong pungent
odour Density 0.86 kg/m3 (1.013 bar ) Melting point −77.73 °C Boiling point −33.34 °C Solubility in water
47% (0 °C) Solubility soluble in chloroform, ether, ethanol, methanol
Structure:
Molecular formula NH3
Molar mass 17.031 g/mol
Appearance Colorless gas
Odour strong pungent odour
Density 0.86 kg/m3 (1.013 bar )
Melting point −77.73 °C
Boiling point −33.34 °C
Solubility in water 47% (0 °C)
Solubility soluble in chloroform, ether, ethanol, methanol
Structure
Molecular shape Trigonal pyramid
Thermo chemistry
Flash point flammable gas (see text)
Explosive limits 15–28%
101.7 Pm
3. Experimental Investigation on Domestic Refrigerator by Shell and Tube Heat Exchanger after …
DOI: 10.9790/1684-12256367 www.iosrjournals.org 65 | Page
Ammonia, or azane, is a compound of nitrogen and hydrogen with the formulae NH3. It is a colorless
gas with a characteristic pungent smell. NH3 boils at −33.34 °C (−28.012 °F) at a pressure of one atmosphere,
so the liquid must be stored under pressure or at low temperature. Household ammonia or ammonium hydroxide
is a solution of NH3 in water. Measured in units of the Baumé scale (density), with 26 degrees baumé (about
30% (by weight) ammonia at 15.5 °C or 59.9 °F) being the typical high-concentration commercial product.
Solvent properties:
Ammonia is miscible with water. In an aqueous solution, it can be expelled by boiling. The aqueous
solution of ammonia is basic. The maximum concentration of ammonia in water (a saturated solution) has a
density of 0.880 g/cm3 and is often known as '.880 ammonia'. Ammonia does not burn readily or sustain
combustion, except under narrow fuel-to-air mixtures of 15–25% air. One of the most characteristic properties
of ammonia is its basicity.
II. Experimental Setup
The experimental test rig has a vapor refrigeration cycle working with refrigerant R-134a it consists of
a compressor, evaporator, air cooled condenser, receiver, expansion valve and two shell and tube heat
exchangers, One placed after condenser and the other after the evaporator. In the present work on the domestic
refrigerator placing of shell and tube heat exchanger after the condenser contains ammonia that absorbs the heat
from the refrigerating fluid coming from condenser. Sub cooling will occur and allow the operating pressure and
temperature to be lowered. The net refrigeration effect and overall performance of the system will increase. The
ammonia that is present in the modified shell and tube heat exchanger is converted from liquid to vapor state.
The vaporized ammonia exchanges heat with the refrigerant coming out from the heat exchanger placed
immediately after the evaporator is converted in to liquid .The cooled ammonia returns back to shell and tube
heat exchanger after the condenser.
Modifications made to the existing system
Heat exchanger (HE-1) placed after the expansion valve in which liquid ammonia converts to vapor
ammonia. Heat exchanger (HE-2) placed after the evaporator in which vapour ammonia converts to liquid. The
ammonia continuously transferred from HE-1 to HE-2 and vice-versa.
Fig 1.3: Proposed System
Fig 1.4: Shell and Tube Heat Exchanger
4. Experimental Investigation on Domestic Refrigerator by Shell and Tube Heat Exchanger after …
DOI: 10.9790/1684-12256367 www.iosrjournals.org 66 | Page
In the above fig.1.4 the liquid - vapor phase refrigerant flows through the tube and the Ammonia flows
outside the tubes but inside the shell (the shell side). Heat is transferred from refrigerant to Ammonia through
the tube walls, either from tube side to shell or vice versa
III. Tabular Column:
Performance
with
Suctionpressure
(bar)
Discharge
pressure(bar)
Temperatureof
vapour
refrigerantbefore
shells(0C)
Inlettemperature
of
compressor(0C)
Outlet
temperatureof
compressor(0C)
Condenseroutlet
temperature
beforeshell
SS0shell(0C
((()S(((shell(0C)Condenseroutlet
temperatureafter
shell(0C)()
Evaporator
temperature(0C)
Coefficientof
performance
Base line 0.9 18.0 - 19.1 78.2 - 42.9 2.6 5.16
Ammonia 0.6 11.0 18.1 25.0 69.5 42.0 39.5 1.7 6.11
Graph 1 Comparison of Heat Rejection Rate for Existing System and Proposed System
Graph 2 Comparison of net refrigeration effect for existing system and proposed system
Graph 3 Comparison of power input per tone of refrigeration for existing system and proposed system
5. Experimental Investigation on Domestic Refrigerator by Shell and Tube Heat Exchanger after …
DOI: 10.9790/1684-12256367 www.iosrjournals.org 67 | Page
Graph 4 Comparison of coefficient of performance for existing system and proposed system
IV. Result And Discussions:
By placing shell and tube heat exchanger after condenser the refrigerant is sub cooled by 2.5 0C when
ammonia is used as coolant. Due to sub cooling the net refrigeration effect is increased and the C.O.P of the
system is increased. The increase in coefficient of performance is 18.4% when ammonia is used as coolant.
Coefficient of performance of refrigerator will be more with ammonia when compared with existing system
References:
[1]. Akintunde, M.A. 2004b. Experimental Investigation of The performance of Vapor Compression Refrigeration Systems. Federal
University of Technology, Akure, Nigeria.
[2]. Eckert, E.R.G.; Goldstein, R.J.; Ibele, W.E.; Patankar, S.V.; Simon, T.W.; Strykowski, P.J.; Tamma, K.K.; Kuehn, T.H.; Bar-
Cohen, A.; Heberlein, J.V.R.; (Sep 1997), Heat transfer- a review of 1994 literature, International Journal of Heat and Mass
Transfer 40-16, 3729-3804.
[3]. Performance enhancement of a household refrigerator by addition of latent heat storage International Journal of Refrigeration,
Volume 31, Issue 5, August 2008, Pages 892-901 Azzouz, K.; Leducq, D.; Gobin, D.
[4]. Akintunde, M.A. 2004b. Experimental Investigation of The performance of Vapor Compression Refrigeration Systems. Federal
University of Technology, Akure, Nigeria.
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[7]. James R. lines . ly Coiled Heat Exchangers offer Advantages GRAHAM MANUFACTURI