MétaCan
Menu
Back to cohort
Record W55108806

Modelling of the flow of refrigerant 134a in capillary tubes

2004· other· en· W55108806 on OpenAlexaboutno aff
Azmahani Sadikin

Bibliographic record

VenueUTHM Institutional Repository (Universiti Tun Hussein Onn Malaysia) · 2004
Typeother
Languageen
FieldEngineering
TopicRefrigeration and Air Conditioning Technologies
Canadian institutionsnot available
Fundersnot available
KeywordsRefrigerantRefrigerationCapillary actionPressure dropMechanicsFlow (mathematics)Tube (container)ThermodynamicsCondenser (optics)Materials scienceEnvironmental scienceMechanical engineeringEngineeringNuclear engineeringPhysicsGas compressor
DOInot available

Abstract

fetched live from OpenAlex

Practical tools for the design of capillary tubes for refrigeration systems employing the traditional CFC-12 and HCFC-22 as refrigerants are widely available. Due to environmental concern of the depletion of ozone layer and global warming, CFCs and HCFCs have to be phased out eventually according to the Montreal Protocol. As a result, a number of alternative refrigerants including HFC-134a have emerged as promising chlorine free alternatives to CFC-12 in domestic refrigerators and freezers. The proper size of a capillary tube with a new refrigerant is a critical factor for the optimum performance of a refrigeration system. This study presents a computer model KAPILARI, which has been developed to predict the length of capillary tube used as an expansion device in small refrigerating and air-conditioning systems. The pressure drop through a capillary tube in the single-phase and two-phase regions is modelled in an attempt to predict the size of capillary tube. The model is based on the governing equations of conservation of mass, energy and momentum. Stoecker's basic model was modified with the consideration of various effects due to sub cooling, choked flow and friction factor used in single-phase region. The developed model has been validated by employing available studies and found to agree well with the experimental data and other mathematical model predictions of HFC-134a. The capability of the program has been tested and simulations are carried out to investigate the effect of varying the operating and design parameters of the system, namely cooling capacity, evaporating temperature, degree of superheat, condensing temperature, degree of subcoo1ing and inner diameter of capillary tube, on the length of the capillary tube. The developed model is an effective tool of capillary tube's 377$ design and optimization for systems using HFC-134a

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Simulation or modeling · Consensus signal: Simulation or modeling
GenreCandidate signal: Empirical · Consensus signal: none
Teacher disagreement score0.692
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0010.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.010
GPT teacher head0.172
Teacher spread0.162 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

Study designSimulation or modeling
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations0
Published2004
Admission routes1
Has abstractyes

Explore more

Same venueUTHM Institutional Repository (Universiti Tun Hussein Onn Malaysia)Same topicRefrigeration and Air Conditioning TechnologiesFrench-language works237,207