Critical evaluation of R134a, R1234yf and R744 in passenger car cooling systems
Bibliographic record
Abstract
The Montreal Protocol on ozone-depleting substances and the Kyoto Protocol to the United Nations Framework Convention on Climate Change are affecting the refrigeration industry. Both documents have banned the use of substances responsible for ozone depletion and global warming. The automotive industry must keep up with these changes. The design of cooling systems in cars must meet the requirements of new refrigerants. In addition, changing the production profile of large car companies towards electric and hybrid cars increases this need. This development has a significant impact on the solutions installed in passenger vehicles. The paper presents a critical assessment of R134a, R1234yf, and R744 in passenger car heat pump systems. The possibility of their use in common air conditioning systems with motor drive and in the heat pump of an electric vehicle was presented. The calculation algorithm of the heat pump system has been developed, showing the influence of the physical properties of refrigerants on efficiency during the process of the designed heat pump system. The impact of using new refrigerants in the car production process has been analyzed and commented on. The influence of thermodynamic and ecological properties of refrigerants on the process of designing a heat pump system using a calculation model was described. Types of heat pump in electric cars and a calculation model were presented.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot 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.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
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".