Microfin tubes are widely used to enhance heat transfer in heat exchangers in order to reduce volumes, costs and refrigerant charge. Much experimental work has been published for the flow of liquids, while some experimental work is available for the...
Environmental concerns are forcing the replacement of commonly used refrigerants, and finding new fluids is a top priority. Soon the R134a will be banned, and the hydro-fluoro-olefin (HFO) R1234ze(E) has been indicated as an alternative due to its sm...
The air conditioning and refrigeration industry is now dealing with an imminent substitution of widely implemented refrigerants having a non-negligible global warming impact. Among the proposed hydrofluoroolefins, R1234ze(E) has thermodynamic and tra...
This study was made to investigate the condensation local heat transfer and adiabatic pressure drop of R134a inside a 2.5 mm outside diameter smooth and microfin tube at low mass flux condition. Data were measured for mass fluxes from 50 to 300 kg m&...
This review study examines flow boiling heat transfer in micro-fin tubes using mixed and pure refrigerants with zero ozone-depleting potential (ODP) and minimal global warming potential (GWP). This investigation focuses on the extraordinary relations...
The flow boiling heat transfer is one of the common phenomenon happening in the industries. The micro-fin tubes are one of the geometries widely used to enhance heat transfer rate in boiling condition. The entropy generation analysis is presented wit...
In response to stringent rules inhibiting the implementation of refrigerants with high global warming impact, alternative candidates should undergo assessments to prove their viability. The mixtures R450A and R454B, being the center of the current fo...
A comparative analysis of the flow boiling characteristics of R450A, R515B, and R1234ze(E) inside a 7.0 mm OD microfin tube was performed. The mass velocity was explored from low values, starting from 50 kg m−2 s−1, up to 400 kg m−2...
The ongoing miniaturization of air conditioning and refrigeration systems, in order to limit, as much as possible, the refrigerant charge, calls for smaller and smaller heat exchangers. Besides, the new environmental regulations are calling for new p...
The present study is focused on identifying the most suitable sequence of machine learning-based models and the most promising set of input variables aiming at the estimation of heat transfer in evaporating R134a flows in microfin tubes. Utilizing th...
This study experimentally investigates the energy, exergy, and economic performance of an enhanced photovoltaic/thermal (PVT) solar collector using micro-finned tubes, twisted-tape inserts, hybrid nanofluid, and nano-enhanced phase-change material (N...
A database for flowing condensation of three hydrocarbons, namely propane (R290), isobutane (R600a), and propylene (R1270), is extended by experimental tests in a smooth tube and two microfinned tubes with an increase of heat exchange area of 1.51 an...
This review presents the nucleate/convective boiling performance for a variety of important low global warming potential (LGWP) alternatives to commonly used high-global warming potential (GWP) refrigerants (such as R-134a, R404A, and R-410A, etc.)....
In this review, the condensation HTCs (heat transfer coefficients) and pressure drop characteristics of some major low-global-warming-potential (GWP) refrigerants alternative to R-134a such as R-1234ze(E), R-1234ze(Z), R-1234yf, R-513A, and R-450A ar...
The condensation heat transfer coefficient of R134a was experimentally studied inside two smooth and four micro-fin tubes. The working conditions and structural parameters of the test tubes were selected as the influencing factors, and the experiment...
This paper presents the two-phase condensation heat transfer and pressure drop characteristics of R-513A as an alternative refrigerant to R-134a in a 9.52-mm OD horizontal microfin copper tube. The test facility had a straight, horizontal test sectio...
In this study, the pressure drop and heat transfer characteristics of smooth tube and internal helically micro-finned tubes with two different fin-to-fin height ratios i.e., equal fin height and alternating fin height, are computationally analysed. T...
A database containing flow boiling heat transfer characteristics of various refrigerants inside micro-fin tubes with different structures under wide-range working conditions was built. Then the influencing mechanisms of refrigerant thermo-physical pr...
Condensation heat transfer characteristics (using R410A as the working fluid) were studied experimentally to evaluate the heat transfer performance in copper and stainless-steel heat transfer tubes (smooth and enhanced). Experiments were carried out...
The use of innovative methods for the design of heating, cooling, and heat storage devices has been mainly oriented in the last decade toward the use of nanofluids, metal foams coupled with working fluids, or phase change materials (PCMs). A network...
Required refrigerant charge in heat pump systems with propane is analyzed. Two systems are compared: the first a direct heat pump, with fin-and-tube heat exchangers, and the second an indirect system, with plate heat exchangers with an additional bri...
As an auxiliary component with the largest energy consumption in the fuel cell power system, the electric air compressor is of great significance to improve the overall efficiency of the system by reducing its power consumption under the premise of m...
This article presents the results of a numerical CFD study of heat exchanger channels with passive heat transfer enhancement methods. Two types of channel geometry were analyzed with different flow turbulization methods. In case I, internal micro-fin...
In this study, a new method of ultrasonic high-frequency percussion (UH-FP) is proposed. Ultra-fine and ultra-long copper tube electrodes cannot be fabricated by traditional processing methods, and the copper tube electrodes fabricated by UH-FP can b...
The article presents the results of numerical studies of heat transfer and pressure drops in a channel with transverse micro-fins. The main aim of the study was to prepare the thermal and flow characteristics of such a channel for a variable longitud...
To enhance the heat-transfer performance of scramjet engines, a numerical simulation was conducted on the heat-transfer process of RP-3 aviation kerosene under supercritical pressure within a horizontal micro-fine circular tube. The intrinsic mechani...