Improved semi-empirical method for determination of heat transfer coefficient in flow boiling in conventional and small diameter tubes

Calculation Method for Flow Boiling and Flow Condensation of R134a and R1234yf in Conventional and Small Diameter Channels

“…Several publications, namely by Ribatski [27], Tibirçá and Ribatski [28], Sardeshpande and Ranade [29], and Alagesan [30] analyse the experimental data for validation of heat transfer coefficient predictions using correlations available in the literature. In the present paper, the experimental results collected from the literature are compared with the predictions of the model [31,32]. Based on the evidence of comparison with the abovementioned experimental data, a correction making use of the reduced pressure effect has been applied to the authors' model to provide feasibly the best consistency of the predictions with the experiments.…”

“…The versatile semi-empirical model to calculate flow boiling and flow condensation due to D. Mikielewicz et al [31,32] has been tested for a significant number of experimental data and has returned satisfactory results for cases of flow boiling processes in numerous fluids. The fundamental hypothesis of the model is the fact that heat transfer during flow boiling with bubble generation can be modelled as a sum of two contributions constituting the total energy dissipation in the flow, namely the energy dissipation due to shearing flow without bubbles and the dissipation resulting from bubble generation.…”

Computer cooling using a two phase minichannel thermosyphon loop heated from horizontal and vertical sides and cooled from vertical side

“…R11 was used as a working fluid (t = 20 • C , p = 0.895×10 5 Pa) [5]. The heat transfer coefficient in flow boiling for minichannels α T P B distributions versus heat fluxq h1 in evaporator (s 0 ≤ s ≤ s 1 ) were obtained numerically with Mikielewicz [10] and Saitoh [12] correlations (Tab. 1).…”

Causality in Models of Thermal Processes in Ship Engine Rooms with the Use of Bond Graph (BG) Method

“…The social growth of expectations in terms of increasing the efficiency of machinery and equipment as well as reducing greenhouse gas emissions and air pollutants forced in recent years the intensification of research and development to improve the efficiency of heat exchange processes [4,18], the structural improvement of working machines and power equipment [7,14,16,24], improving the quality of diagnostics of these devices [11,12] and the improvement of efficiency of the manufacturing process of machine elements [6,9]. One of the more complex energy systems, which is covered by the above-mentioned development work is a ship's engine room.…”