Engineering › Mechanical Engineering

Refrigeration and Air Conditioning Technologies

Works Count: 51079

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Description

This cluster of papers focuses on refrigeration systems and technologies, with an emphasis on refrigerants, ejectors, CO2 heat pumps, vapor compression systems, low-GWP alternatives, thermodynamic analysis, energy efficiency, environmental impact, and heat pump technology. The papers cover a wide range of topics including experimental validation, numerical investigations, performance predictions, and environmental considerations in the field of refrigeration and heat pump systems.

Keywords

Refrigerants; Ejectors; CO2 Heat Pumps; Vapor Compression Systems; Low-GWP Alternatives; Thermodynamic Analysis; Energy Efficiency; Environmental Impact; Heat Pump Technology; CFD Modeling

Ejector refrigeration: A comprehensive review

2015-09-19

Giorgio Besagni , Riccardo Mereu , Fabio Inzoli

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Review of recent developments in advanced ejector technology

2015-11-04

Stefan Elbel , Neal Lawrence

Advances in heat pump systems: A review

2010-07-11

K.J. Chua , S.K. Chou , Wanyou Yang

Revival of carbon dioxide as a refrigerant

1994-01-01

G Lorentzen

Applications of artificial neural networks for refrigeration, air-conditioning and heat pump systems—A review

2011-12-02

M. Mohanraj , S. Jayaraj , C. Muraleedharan

Food transport refrigeration – Approaches to reduce energy consumption and environmental impacts of road transport

2008-07-03

S.A. Tassou , G. De-Lille , Y.T. Ge

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Achieving better energy-efficient air conditioning – A review of technologies and strategies

2012-12-14

K.J. Chua , S.K. Chou , Wanyou Yang +1 more

Performance prediction of steam ejector using computational fluid dynamics: Part 1. Validation of the CFD results

2006-11-28

Thanarath Sriveerakul , Satha Aphornratana , K. Chunnanond

The use of natural refrigerants: a complete solution to the CFC/HCFC predicament

1995-03-01

G Lorentzen

The next generation of refrigerants – Historical review, considerations, and outlook

2008-02-13

J.M. Calm

Experimental validation of a prototype ejector designed to reduce throttling losses encountered in transcritical R744 system operation

2007-08-08

Stefan Elbel , Pega Hrnjak

Numerical investigation of geometry parameters for design of high performance ejectors

2008-05-11

Yinhai Zhu , Wenjian Cai , Changyun Wen +1 more

A new approach to the exergy analysis of absorption refrigeration machines

2007-12-05

Tatiana Morosuk , George Tsatsaronis

CO2-heat pump water heater: characteristics, system design and experimental results

1998-05-01

Petter Nekså , Håvard Rekstad , Golbon Zakeri +1 more

Thermodynamic analysis of optimal condensing temperature of cascade-condenser in CO2/NH3 cascade refrigeration systems

2006-06-06

Tzong-Shing Lee , Chenghao Liu , Tung-Wei Chen

Review of alternative cooling technologies

2013-12-19

J. Steven Brown , Piotr A. Domanski

Design of Cooler Condensers for Mixtures of Vapors with Noncondensing Gases

1934-11-01

A. P. Colburn , O. A. Hougen

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDesign of Cooler Condensers for Mixtures of Vapors with Noncondensing GasesA. P. Colburn and O. A. HougenCite this: Ind. Eng. Chem. 1934, 26, 11, 1178–1182Publication Date (Print):November … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDesign of Cooler Condensers for Mixtures of Vapors with Noncondensing GasesA. P. Colburn and O. A. HougenCite this: Ind. Eng. Chem. 1934, 26, 11, 1178–1182Publication Date (Print):November 1, 1934Publication History Published online1 May 2002Published inissue 1 November 1934https://pubs.acs.org/doi/10.1021/ie50299a011https://doi.org/10.1021/ie50299a011research-articleACS PublicationsRequest reuse permissionsArticle Views2290Altmetric-Citations259LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts

Ozone depletion and global warming: Case for the use of natural refrigerant – a review

2012-11-03

Bukola Olalekan Bolaji , Zhongjie Huan

Investigation and improvement of ejector refrigeration system using computational fluid dynamics technique

2007-05-30

Kulachate Pianthong , Wirapan Seehanam , Masud Behnia +2 more

Ejectors: applications in refrigeration technology

2003-11-23

K. Chunnanond , Satha Aphornratana

Transformations of Galaxies. II. Gasdynamics in Merging Disk Galaxies

1996-11-01

Joshua E. Barnes , Lars Hernquist

In mergers of disk galaxies, gas plays a role quite out of proportion to its relatively modest contribution to the total mass. To study this behavior, we have included gasdynamics … In mergers of disk galaxies, gas plays a role quite out of proportion to its relatively modest contribution to the total mass. To study this behavior, we have included gasdynamics in self-consistent simulations of collisions between equal-mass disk galaxies. The large-scale dynamics of bridge- and tail-making, orbit decay, and merging are not much altered by the inclusion of a gaseous component. However, tidal forces during encounters cause otherwise stable disks to develop bars, and the gas in such barred disks, subjected to strong gravitational torques, flows toward the central regions where it may fuel the kiloparsec-scale starbursts seen in some interacting disk systems. Similar torques on the gas during the final stages of a collision yield massive gas concentrations in the cores of merger remnants, which may be plausibly identified with the molecular complexes seen in objects such as NGC 520 and Arp 220. This result appears insensitive to the detailed microphysics of the gas, provided that radiative cooling is permitted. The inflowing gas can dramatically alter the stellar morphology of a merger remnant, apparently by deepening the potential well and thereby changing the boundaries between the major orbital families.

A theoretical and experimental study of a small-scale steam jet refrigerator

1995-07-01

I. Eames , Satha Aphornratana , Hani Haider

Review of solar refrigeration and cooling systems

2013-08-23

Ioan Sârbu , Călin Sebarchievici

Exergy analysis, parametric analysis and optimization for a novel combined power and ejector refrigeration cycle

2008-10-03

Yiping Dai , Jiangfeng Wang , Lin Gao

Energy and exergy analysis of single effect and series flow double effect water–lithium bromide absorption refrigeration systems

2009-01-30

S.C. Kaushik , Akhilesh Arora

Numerical and experimental investigations on supersonic ejectors

2004-09-14

Yann Bartosiewicz , Zine Aidoun , P. Desevaux +1 more

Solar air conditioning in Europe—an overview

2005-04-20

Constantinos A. Balaras , G. Grossman , Hans‐Martin Henning +4 more

Efficiencies of transcritical CO2 cycles with and without an expansion turbine

1998-11-01

Douglas M. Robinson , Eckhard A. Groll

A review on exergy analysis of vapor compression refrigeration system

2011-01-13

Jamal Uddin Ahamed , R. Saidur , H.H. Masjuki

Environment friendly alternatives to halogenated refrigerants—A review

2008-08-29

M. Mohanraj , S. Jayaraj , C. Muraleedharan

A correlation of optimal heat rejection pressures in transcritical carbon dioxide cycles

2000-06-01

Shengming Liao , Tianshou Zhao , Arne Jakobsen

A review of heat pump water heating systems

2008-09-14

Arif Hepbaşlı , Yildiz Kalincı

Fundamental process and system design issues in CO2 vapor compression systems

2003-12-19

Man-Hoe Kim , Jostein Pettersen , Clark W. Bullard

Transcritical CO2 refrigeration cycle with ejector-expansion device

2005-02-17

Daqing Li , Eckhard A. Groll

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Optimization of a transcritical CO2 heat pump cycle for simultaneous cooling and heating applications

2004-08-05

Jahar Sarkar , Souvik Bhattacharyya , M. Gopal

A 1-D analysis of ejector performance

1999-08-01

Bin‐Juine Huang , Jan-Shun Chang , C.P. Wang +1 more

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An Investigation of Ejector Design by Analysis and Experiment

1950-09-01

J. H. Keenan , E. P. Neumann , F. Lustwerk

Abstract A one-dimensional method of analysis of jet pumps or ejectors is presented. The analysis considers mixing of the primary and secondary streams at constant pressure, and mixing of the … Abstract A one-dimensional method of analysis of jet pumps or ejectors is presented. The analysis considers mixing of the primary and secondary streams at constant pressure, and mixing of the streams at constant area. For the analytical conditions considered, better performance can be obtained when constant-pressure mixing is employed. A comparison between experimental and analytical results shows good agreement over a broad range of variables. Some experimental data on the length of tube required for mixing of the two streams are presented. A method for jet-pump design is given.

Refrigeration Systems and Applications

2010-05-14

İbrahim Dinçer , Mehmet Kanoğlu

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Energy performance evaluation of R1234yf, R1234ze(E), R600a, R290 and R152a as low-GWP R134a alternatives

2016-09-22

Daniel Sánchez , Ramón Cabello , Rodrigo Llopis +3 more

Limited options for low-global-warming-potential refrigerants

2017-02-17

Mark O. McLinden , J. Steven Brown , Riccardo Brignoli +2 more

Abstract Hydrofluorocarbons, currently used as refrigerants in air-conditioning systems, are potent greenhouse gases, and their contribution to climate change is projected to increase. Future use of the hydrofluorocarbons will be … Abstract Hydrofluorocarbons, currently used as refrigerants in air-conditioning systems, are potent greenhouse gases, and their contribution to climate change is projected to increase. Future use of the hydrofluorocarbons will be phased down and, thus replacement fluids must be found. Here we show that only a few pure fluids possess the combination of chemical, environmental, thermodynamic, and safety properties necessary for a refrigerant and that these fluids are at least slightly flammable. We search for replacements by applying screening criteria to a comprehensive chemical database. For the fluids passing the thermodynamic and environmental screens (critical temperature and global warming potential), we simulate performance in small air-conditioning systems, including optimization of the heat exchangers. We show that the efficiency-versus-capacity trade-off that exists in an ideal analysis disappears when a more realistic system is considered. The maximum efficiency occurs at a relatively high volumetric refrigeration capacity, but there are few fluids in this range.

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Refrigeration Systems and Applications

2017-03-25

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Techno-economic analysis of air source heat pump applied for space heating in northern China

2017-07-05

Qunli Zhang , Lin Zhang , Jinzhe Nie +1 more

High temperature heat pumps: Market overview, state of the art, research status, refrigerants, and application potentials

2018-03-31

Cordin Arpagaus , Frédéric Bless , Michael Uhlmann +2 more

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Natural and synthetic refrigerants, global warming: A review

2018-04-24

Naeem Abas , Ali Raza Kalair , Nasrullah Khan +3 more

A comprehensive review of ejector design, performance, and applications

2019-02-15

Bourhan Tashtoush , Moh’d A. Al-Nimr , Mohammad A. Khasawneh

CO2 heat pump systems

2002-06-01

Petter Nekså

Insight into the heat and mass transfer effects on the transonic condensing flow in compressor applied to compressed air energy storage system

2025-06-23

Guojie Zhang , Yifan Yang , Zunlong Jin +1 more | Energy Conversion and Management

Energy Savings Potential of Multipurpose Heat Pumps in Air-Handling Systems

2025-06-21

Eva Schito , Paolo Conti | Energies

Multipurpose heat pumps are devices able to provide simultaneously heating and cooling requirements. These devices concurrently provide useful thermal energy at condenser and evaporator with a single electrical energy input, … Multipurpose heat pumps are devices able to provide simultaneously heating and cooling requirements. These devices concurrently provide useful thermal energy at condenser and evaporator with a single electrical energy input, potentially achieving energy savings as heat-recovery and co-generative technology. Despite their potential contribution to the energy transition goals as both renewable and energy-efficient technology, their use is not yet widespread. An application example for multipurpose heat pumps is air handlers, where cooling and reheat coils are classically fed by separate thermal generators (i.e., boiler, heat pumps, and chillers). This research aims at presenting the energy potential of multipurpose heat pumps as thermal generators of air handler units, comparing their performances with a classic separate configuration. A museum in the Mediterranean climate is selected as a reference case, as indoor temperature and relative humidity must be continuously controlled by cold and hot coils. The thermal loads at building and air handler level are evaluated through TRNSYS 17 and MATLAB 2022b, through specific dynamic models developed according to manufacturer’s data. An integrated building-HVAC simulation, on the cooling season with a one-hour timestep, demonstrates the advantages of the proposed technology. Indeed, the heating load is almost entirely provided by recovering energy at the condenser, and a 22% energy saving is obtained compared to classic separate generators. Furthermore, a sensitivity analysis confirms that the multipurpose heat pump outperforms separate generation systems across different climates and related loads, with consistently better energy performance due to its adaptability to varying heating and cooling demands.

Multi-component gas recirculation modeling approach for ejector-based passive anode system of vehicle proton exchange membrane fuel cell under full operating conditions

2025-06-21

Haowei Guo , Lei Wang , Chen Wang +2 more | Journal of Power Sources

Benefits assessment of a dual-intake-port sliding vane rotary expander replacing the high pressure throttling valve of a trans-critical CO2 refrigeration unit

2025-06-20

Fabio Fatigati , Roberto Cipollone | Energy Conversion and Management

Comprehensive evaluation of energy, exergy and economic performance of transcritical CO2/R41 air-source heat pump water heater based on entropy weight method

2025-06-20

Dong Wang , Rongrong Zhou , Zuo-Yu Sun +4 more | Energy

Dynamic Analysis of Two-Wheel Bleed Air Environment Control System of the Aircraft

2025-06-19

Chandra Shekhar Sharma , C. Ranganayakulu | Research Square (Research Square)

<title>Abstract</title> Dynamic analysis of the environment control system plays a crucial role in improving system performance and control. This article describes the Dynamic analysis of a two-wheel bleed air environment … <title>Abstract</title> Dynamic analysis of the environment control system plays a crucial role in improving system performance and control. This article describes the Dynamic analysis of a two-wheel bleed air environment control system for the aircraft. An environment control system library of Dymola software was used to develop the Dynamic model of a 2-wheel bleed air environment control system. Dymola is a commercial 1-D dynamic simulation software based on the Modelica language. An analysis was carried out on the key components of the two-wheel bleed air high-pressure water separator environment control system. The Dynamic response obtained from the model in terms of hot side heat flow rate for the core compact heat exchangers, outlet temperature on the hot and cold side for the heat exchangers, the outlet temperature of the cold air unit, as well as corrected flow and corrected speed of the cold air unit. The dynamic response is also obtained for the shaft power, torque, and angular speed. As per the literature, a separate steady-state analysis has been done in the MATLAB code for validation due to the unavailability of a Dynamic study on a two-wheel high-pressure water separator bleed air environment control system. The simulation results demonstrate a strong level of accuracy when compared to the steady-state analysis. The system-level Dynamic response was obtained around 26 seconds, 52 seconds, and 78 seconds at mass moment of inertia of the cold air unit shaft 0.01 kgm2, 0.02 kgm2, and 0.03 kgm2, respectively, validated against MATLAB steady-state results. The Dynamic model developed can be utilized during the initial design phase of the system when actual experimental data is unavailable.

Thermal Performance Characterization Of Dry Gas Seals In a sCO2 Compressor

2025-06-19

Rahul A. Bidkar , Uttara Kumar , Xiaohua Zhang +5 more | Journal of Turbomachinery

Abstract Commercially available dry gas seals (DGS) are the seal-of-choice for shaft-end sealing locations in compressors used in the oil and gas industry, and supercritical CO2 power cycles. DGS reliability … Abstract Commercially available dry gas seals (DGS) are the seal-of-choice for shaft-end sealing locations in compressors used in the oil and gas industry, and supercritical CO2 power cycles. DGS reliability is tied to how well the 2 to 7 micron gas/supercritical fluid film is sustained under varying pressure, thermal, and speed conditions. Recent sCO2 turbomachinery development efforts have experienced a couple of catastrophic DGS failures at the compressor shaft-end locations. A suspected root cause of these DGS failures is thermal deformations caused by the excessive windage heating expected with the supercritical CO2 working fluid when the compressor operates at high pressures and high rotational speeds. In this paper, we investigate the thermal behavior of the DGS operating in a typical sCO2 compressor. Specifically, we present test data on a specially instrumented, commercially available DGS operating in the GE-SwRI sCO2 compressor operating under various mission points. Test data shows higher than expected temperatures (about 190 deg C) in the cavities surrounding the DGS, which provides useful insights to turbomachinery designers for designing seal cavities. Furthermore, we compare the measured temperatures with the predictions of a steady-state thermal model of the GE-SwRI sCO2 compressor. The thermal model uses a 1D flow advection network with cavity swirl solvers, windage and heat transfer coefficients for sCO2 flow exchanging heat with the surrounding structure. The predictions of the thermal model match reasonably well with the measured temperature data, thereby providing validation to the novel sCO2 thermal modeling assumptions.

Experimental study on the performance of an auto-cascade refrigeration system integrating fractional condensation and flash separation

2025-06-19

Yinlong Li , Jing Dongliang , Yue Li +2 more | Energy

Comparative Analysis of Transcritical CO2 Heat Pump Systems With and Without Ejector: Performance, Exergy, and Economic Perspective

2025-06-19

Xiang Qin , Shuting Lei , Heyu Liu +4 more | Energies

To promote renewable energy utilization and enhance the environmental friendliness of refrigerants, this study presents a novel experimental investigation on a transcritical CO2 double-evaporator heat pump water heater integrating both … To promote renewable energy utilization and enhance the environmental friendliness of refrigerants, this study presents a novel experimental investigation on a transcritical CO2 double-evaporator heat pump water heater integrating both air and water sources, designed for high-temperature hot water production. A key innovation of this work lies in the integration of an ejector into the dual-source system, aiming to improve system performance and energy efficiency. This study systematically compares the conventional circulation mode and the proposed ejector-assisted circulation mode in terms of system performance, exergy efficiency, and the economic payback period. Experimental results reveal that the ejector-assisted mode not only achieves a higher water outlet temperature and reduces compressor power consumption but also improves the system’s exergy efficiency by 6.6% under the condition of the maximum outlet water temperature. Although the addition of the ejector increases initial manufacturing and maintenance costs, the payback periods of the two modes remain nearly the same. These findings confirm the feasibility and advantage of incorporating an ejector into a transcritical CO2 compression/ejection heat pump system with integrated air and water sources, offering a promising solution for efficient and environmentally friendly high-temperature water heating applications.

Enhancing dedicated outdoor air system heating performance in cold climates with integrated enthalpy heat exchanger and heat pump

2025-06-19

Shengwen Wang , Jiahao Cheng , Chun‐Lu Zhang | Energy and Buildings

Sound model of an acoustic improved air to water heat pump

2025-06-18

Thorsten Schmidt , Dirk Müller | Acta Acustica

Heat pumps represent an essential component of the energy transition. While they are effective in generating heat, they also generate sound, which has the potential to cause annoyance. Therefore, it … Heat pumps represent an essential component of the energy transition. While they are effective in generating heat, they also generate sound, which has the potential to cause annoyance. Therefore, it is essential to enhance the transparency of the sound behavior. Analyses were performed to identify the factors influencing sound levels at both the component and system levels. A total of three refrigerant compressors were examined with the objective of determining the most acoustically efficient components currently available and the key factors influencing acoustics. Two low-noise axial fans are used to illustrate the differing sound characteristics when used in a heat pump application. Based on component tests and measurements at the heat pump system level, the speeds of the compressor and fan were confirmed as significant factors influencing the sound emissions of air-to-water heat pumps. In addition, the flow temperature and the operating point of the fan were identified as factors influencing. The results were employed to develop an acoustically improved heat pump demonstrator. A sound model could be developed that is capable of describing the sound behavior for a wide range of operating conditions. This methodology allows for increased transparency in sound behavior. Different behaviors of heat pumps can be demonstrated on the basis of the model, and discussions on the definition of maximum sound specifications can be held on the basis of data. Sound emissions should not only be linked to heat output, as this increases the uncertainty of comparability. A transparent representation of the speeds is strongly recommended.

Enhancing cop of electric vehicle cooling systems using adsorption heat pumps

2025-06-18

Rami Habash , Gamze Gediz İliş , Şaban Ünal +1 more | Thermal Science and Engineering Progress

Parametric Effects of Mixing Channel Geometry on Entrainment Characteristics of Ejector in R410A Heat Pump Systems

2025-06-18

Yuying Wang , Zhengdao Zhou , Meiyuan Yang +3 more | Processes

The two-phase ejector has gained prominence in heat pump systems as a device that effectively mitigates throttling losses through expansion work recovery. This investigation employs three-dimensional computational fluid dynamics (CFD) … The two-phase ejector has gained prominence in heat pump systems as a device that effectively mitigates throttling losses through expansion work recovery. This investigation employs three-dimensional computational fluid dynamics (CFD) simulations to analyze the parametric effects of the mixing channel geometry on the entrainment characteristics in an R410A ejector. After validating the model according to the experimental data, the parameter analysis was carried out, and four key geometric parameters were changed within a certain range: the nozzle exit position (NXP = 13–19 mm), the pre-mixing channel convergent angle (CA = 20–60°), the diameter ratio (DDR = 5.0–7.1), and the length-to-diameter ratio (LDR = 8.9–12.4). Multi-variable optimization studies revealed optimal geometric configurations at NXP = 17 mm (about 3.5Dmix), CA = 30°, DR = 6.4, and LDR = 11.1, yielding an optimized mass entrainment ratio enhancement of 23.6% compared to baseline designs. This research provides actionable guidelines for the design of high-efficiency ejector components for heat pump applications.

Performance Enhancement of Refrigeration Systems Using Heat Pipe Subcoolers: An Experimental Investigation

2025-06-17

Channarong Wantha | Heat Transfer

ABSTRACT This study investigates the performance enhancement of R134a vapor compression refrigeration systems through externally integrated heat pipe subcoolers (HPSCs). It addresses the growing demand for energy‐efficient refrigeration by applying … ABSTRACT This study investigates the performance enhancement of R134a vapor compression refrigeration systems through externally integrated heat pipe subcoolers (HPSCs). It addresses the growing demand for energy‐efficient refrigeration by applying a passive subcooling technique that requires no internal system modifications. Four HPSC modules, each comprising three heat pipes and two heat sinks, were installed in series between the condenser outlet and the capillary tube. Experiments conducted at evaporator temperatures of 36°C and 42°C evaluated their effects on cooling capacity, power consumption, and coefficient of performance (COP). The results show that cooling capacity improved by 21%–37% at 36°C and 0.4%–32% at 42°C. At the optimal configuration using four HPSC modules, power consumption changed by only 0.077% at 36°C and 0.171% at 42°C. The normalized COP values increased to 1.38 and 1.32 at 36°C and 42°C, respectively, confirming the effectiveness of passive subcooling in enhancing system efficiency. Unlike previous approaches that required internal modifications or electrical power input, this study offers a simple, passive external retrofit solution suitable for practical subcooling applications without compromising system integrity.

Body Force Modelling of a Multi-Stage High-Pressure Compressor Under Inlet Distortion

2025-06-17

Carmela De Crea , Julien Marty , Raphaël Barrier +2 more | International Journal of Turbomachinery Propulsion and Power

The present work aims to propose a new calibration strategy of the Hall–Thollet Body Force (BF) model to simulate the flow in multi-stage compressors and to capture inlet distortion effects … The present work aims to propose a new calibration strategy of the Hall–Thollet Body Force (BF) model to simulate the flow in multi-stage compressors and to capture inlet distortion effects within the machine. Both global (0D) and radial (1D) correction terms are introduced and calibrated to improve predictions in multi-stage compressors, accounting for highly interacting, highly loaded blades, falling outside the validity range of the model’s original coefficients. The modified model has been tested on the 3.5-stage high-pressure compressor CREATE, for which experimental data are available. The modified model is then employed to study different patterns of inlet distortion. The results show a very good agreement between Unsteady Reynolds-Averaged Navier–Stokes (URANS) simulations and Body Force calculations in terms of performance, key quantities along the radial and circumferential directions and distortion transfer across the compressor.

Optimization of Rib on the Housing Internal Surface for Improved Heat Dissipation Performance of Linear Compressors

2025-06-15

S.-Y. Oh , Young-Lim Lee | Journal of The Korean Society of Manufacturing Technology Engineers

EXPERIMENTALLY VALIDATED STUDIES OF THERMOELECTRIC GENERATORS INSTALLED ON A COMPRESSOR TEST BENCH

2025-06-14

A. Săvescu , Alexandru M. Morega , Mihaela Roman +1 more | REVUE ROUMAINE DES SCIENCES TECHNIQUES — SÉRIE ÉLECTROTECHNIQUE ET ÉNERGÉTIQUE

This paper presents preliminary experimental work on a twin-screw compressor, aiming to validate numerical studies and demonstrate the potential of thermoelectric energy harvesting. Considering two thermoelectric modules, the experimental validations … This paper presents preliminary experimental work on a twin-screw compressor, aiming to validate numerical studies and demonstrate the potential of thermoelectric energy harvesting. Considering two thermoelectric modules, the experimental validations are conducted in an industrially relevant environment on a test bench for industrial air and gas compressors. The digital twin was simulated using finite element analysis, provided with a heat sink, and a fully coupled heat transfer and electric field was solved to assess the thermoelectric effect. This allows for complete modeling of the Peltier-Seebeck-Thomson effects. The compressor vibrations are also introduced for structural analysis to ascertain that the bismuth telluride thermoelectric modules are safe to use under sinusoidal mechanical vibrations. The thermoelectric generators are screwed onto the hottest part of the compressor skid, specifically the multiplier gearbox cover, which is splashed with hot lubrication oil from within. After the thermal stabilization of the compressor, we obtained a constant series voltage of around 0.4 VDC from the two thermoelectric generators, and the series current was measured to a value of 115 mA.

Investigation on formation, evolution, and performance impact of mixing layer in the zeotropic mixture ejector

2025-06-13

Yingying Tan , Kai Zhang , Lin Wang +2 more | Energy

Semi-empirical performance assessment of a transcritical CO2 system combined with a heat-driven Ejector Refrigeration System (ERS) using hydrocarbons as a subcooling solution for low-temperature refrigeration applications

2025-06-13

Miguel Ávila-Gutiérrez , Bernardo Peris , Francisco José Sánchez de la Flor +1 more | Energy Conversion and Management

One Mixture to Rule Them All: Enhancing Efficiency and Standardization of Industrial High-Temperature Heat Pumps

2025-06-13

Philip Widmaier , Leon P. M. Brendel , Stefan S. Bertsch +2 more | ACS Engineering Au

Experimental Analysis of Thermodynamic Performance for 2.5 kW Split Inverter Air Conditioning Unit with R-410A

2025-06-12

I Gede Artha Negara , I Wayan Temaja , Luh Putu Ike Midiani +3 more | International Journal of Automotive and Mechanical Engineering

This research aims to investigate the thermodynamic performance, including temperature differential properties and energy efficiency ratio (EER) of the air conditioning cooling system. A 2.5 kW split inverter air conditioning … This research aims to investigate the thermodynamic performance, including temperature differential properties and energy efficiency ratio (EER) of the air conditioning cooling system. A 2.5 kW split inverter air conditioning with R-410A was applied in this research for investigation and integrated with a microcontroller ATmega 2560 for data acquisition. The investigation was carried out between temperature setpoint of 16°C and 20°C. An online psychrometric chart calculator was employed in this research to facilitate the calculation of thermodynamic properties. The results showed that the average temperature differential across all the temperature setpoint was found to be 11°C to 12.89°C. This result indicated an ability to exceed the minimum tolerance allowed for evaporator temperature differential standards. Moreover, the highest result of the EER of the air conditioning system was 13.87 at a temperature setpoint of 20°C. The research revealed that all temperature setpoint ranging from 16°C to 20°C yielded EER values within the range of 8 to 15, which is widely recognized as the efficient operational range for residential air conditioning applications. In addition, this air conditioning system has better energy efficiency and cost savings over the lifetime of the cooling system. The integration of microcontroller technology in this research facilitated the real-time recording of each investigation parameter. This approach enhanced the efficiency, complexity, and reliability of the experimental investigation of the air conditioning system.

Accurate and streamlined approach for modelling hermetic reciprocating compressors

2025-06-11

J Wang | Research Square (Research Square)

<title>Abstract</title> This study presents a comprehensive and streamlined approach for accurately modelling the performance of hermetic reciprocating compressors, with a focus on addressing limitations in existing models under variable-speed conditions. … <title>Abstract</title> This study presents a comprehensive and streamlined approach for accurately modelling the performance of hermetic reciprocating compressors, with a focus on addressing limitations in existing models under variable-speed conditions. Traditional compressor models sometimes fail to capture the influence of motor frequency, particularly at low-speed operations where performance variations are significant. To overcome these gaps, a numerical modelling framework was developed using 1-D and 2-D polynomial regressions to represent volumetric and isentropic efficiencies as functions of both compression ratio and motor speed frequency. The modelling process utilizes input data from manufacturer tools and thermodynamic databases to cover a wide range of operating conditions. A case study involving the Bitzer 4HTE-20K CO₂ compressor demonstrates that the proposed speed-driven compressor model improves accuracy, particularly in the low-frequency range below 40 Hz. The proposed numerical model with predictions of compressor power input and discharge temperature has been validated against published experimental data within a ± 10% error margin. This refined approach enhances simulation precision by up to 19.4% at low-speed motor frequencies, offering a practical and reliable tool for academics, industry professionals, and system designers to accurately predict the performance of hermetic reciprocating compressors used in refrigeration and heat pump applications across diverse operational scenarios.

Thermal Equilibrium Time Study Apparatus Using Arduino

2025-06-07

Aditya Murlidhar Wanaskar | International Journal for Research in Applied Science and Engineering Technology

Knowing how heat passes from one object to another is an important aspect of learning about physics, and the concept of thermal equilibrium, where two bodies reach the same temperature … Knowing how heat passes from one object to another is an important aspect of learning about physics, and the concept of thermal equilibrium, where two bodies reach the same temperature and do not exchange heat anymore. We designed a basic and cost-efficient thermal equilibrium laboratory setup using an Arduino to simplify this concept in order to better observe and conduct research on it. The main objective of this project is to create a practical learning device that demonstrates thermal equilibrium in real time. This may be helpful in school labs or small experiments to demonstrate to students how heat moves and levels off between two objects. In this setup, two temperature sensors are connected to an Arduino microcontroller. The sensors are placed on two objects of different initial temperatures. The Arduino reads and compares the temperatures continuously. When the temperatures are equal or very close, the Arduino turns on an LED light to indicate that thermal equilibrium has been reached. This technique makes the observation and study of thermal equilibrium easy by removing the requirement for complicated equipment. The use of Arduino provides flexibility, automation, and real-time monitoring. In general, the concept brings together fundamental physics and simple electronics to make a helpful and informative device.

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Enhanced Energy Efficiency in Dual-Evaporator Refrigerators: Experimental Insights into Parallel Cooling Cycle Optimization

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