Experimental investigation of heat and mass transfer characteristics in direct contact exchanger

Барабаш, Петр Алексеевич; Solomakha, Andrii; Sereda, Volodymyr

doi:10.1016/j.ijheatmasstransfer.2020.120359

Cited by 17 publications

(4 citation statements)

References 22 publications

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“…Several times less moisture evaporates from the surface of the droplets in the airflow (the evaporation share from the surface of the droplets is usually less than 20%) than from the liquid layer surface on the blades and compressor housing [50]. (4) Mechanical losses due to the drop acceleration of the flow and rotating blades' deceleration of the impellers drop by their repeated deposition and surface failure of the blades and housing, as well as friction, liquid layer on the blades' surface, and compressor housing [22,51]. As a result, the stage's internal efficiency and the compressor are reduced [52].…”

Section: Literature Reviewmentioning

confidence: 99%

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Investigation of Thermopressor with Incomplete Evaporation for Gas Turbine Intercooling Systems

Løvås

Konovalov

et al. 2022

Energies

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One of the promising ways to increase fuel and modern gas turbine energy efficiency is using cyclic air intercooling between the stages of high- and low-pressure compressors. For intercooling, it is possible to use cooling in the surface heat exchanger and the contact method when water is injected into the compressor air path. In the presented research on the cooling contact method, it is proposed to use a thermopressor that implements the thermo-gas-dynamic compression process, i.e., increasing the airflow pressure by evaporation of the injected liquid in the flow, which moves at near-sonic speed. The thermopressor is a multifunctional contact heat exchanger when using this air-cooling method. This provides efficient high-dispersion liquid spraying after isotherming in the high-pressure compressor, increasing the pressure and decreasing the air temperature in front of the high-pressure compressor, reducing the work on compression. Drops of water injected into the air stream in the thermopressor can significantly affect its characteristics. An increase in the amount of water increases the aerodynamic resistance of the droplets in the stream. Hence, the pressure in the flow parts of the thermopressor can significantly decrease. Therefore, the study aims to experimentally determine the optimal amount of water for water injection in the thermopressor while ensuring a positive increase in the total pressure in the thermopressor under conditions of incomplete evaporation. The experimental results of the low-consumption thermopressor (air consumption up to 0.52 kg/s) characteristics with incomplete liquid evaporation in the flowing part are presented. The research found that the relative water amount to ensure incomplete evaporation in the thermopressor flow part is from 4 to 10% (0.0175–0.0487 kg/s), without significant pressure loss due to the resistance of the dispersed flow. The relative increase in airflow pressure is from 1.01 to 1.03 (5–10 kPa). Based on experimental data, empirical equations were obtained for calculating the relative pressure increase in the thermopressor with evaporation chamber diameters of up to 50 mm (relative flow path length is from 3 to 10 and Mach number is from 0.3 to 0.8).

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Section: Literature Reviewmentioning

confidence: 99%

“…Another effective spraying method for a highly dispersed flow is using a liquid that is superheated relative to the saturation temperature. At the same time, the spray efficiency is ensured by the instantaneous evaporation process and, as a result, the liquid droplet's effective crushing [51,56].…”

Section: Literature Reviewmentioning

confidence: 99%

Investigation of Thermopressor with Incomplete Evaporation for Gas Turbine Intercooling Systems

Løvås

Konovalov

et al. 2022

Energies

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“…Wijeysundera et al [6] developed an ice slurry generation system with DCHT between water and the coolant (Fluorinert FC-84) and found that the efficiency of ice fabrication increased by about 40 percent. Barabash et al [7] introduced the DCHT technology in cooling towers and for cooling gas flow; they declared that the presence of DCHT can obviously improve the heat transfer efficiency. Mahood et al [2] investigated the heat transfer efficiency, and hence the cost of a three-phase direct-contact condenser, and found that its investment expenses were 30 times lower than those of the corresponding surface condenser (shell-and-tube condenser).…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation on Enhanced Heat Transfer and Flow Characteristics in Direct-Contact Heat Exchanger: A Novel Kenics Static Mixer

Zhao

Zhang

Wang

et al. 2023

International Journal of Energy Research

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In this paper, a novel Kenics static mixer applied in a direct-contact heat exchanger (DCHE) was proposed in order to enhance the heat transfer efficiency. The computational fluid dynamics (CFD) simulation method was adopted to investigate the effect of the continuous phase and dispersed phase on direct-contact heat transfer (DCHT) in the Kenics static mixer. The perforation index (PI) was introduced to depict the performance of the Kenics static mixer, and the effect of different numbers of openings at three initial heat transfer temperature differences (at the inlet of the continuous and dispersed phases) was studied. The simulation results showed that under the same working conditions, a larger initial temperature difference would result in greater differences in the fluid uniformity index (UI), turbulence intensity, and time evolution of a gaseous working substance. The increase of hole numbers and decrease of hole diameters can optimize the DCHT. Under three initial temperature differences, the heat transfer efficiency for the 6-hole and 9-hole Kenics DCHEs was about 20% higher than the Kenics DCHE without holes.

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“…Tungsten-copper and iron based chromel alloy were effectively utilized for temperature applications 3 . In direct contact type heat exchanger, chromel thermocouple was used to find the water temperature at the bottom of heat exchanger to withstand corrosion 4 . Tantalum carbide (TaCx) was used to enrich the carbon content of the material and also to strengthen the interfacial alloying elements through different compositions.…”

Section: Introductionmentioning

confidence: 99%

Tribological Behaviors Analysis of Synthesized Chromel Composite

Fazil¹,

Suresh²

2022

Mat. Res.

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This paper makes an investigation on the synthesis of tantalum carbide (TaC x ) based chromel composites and their tribological behaviour using pin on disc under various load conditions. The reinforced chromel alloy with TaC x was prepared at the rate of 0, 3 and 6 wt.% of TaC using stir casting route. The wear resistance of composites was found to improve with the increase in weight percentage of TaC. The wear properties of Chromel-TaC x composite were enhanced due to the presence of 6% TaC. The wear worn out surface of chromel composite was studied through microstructures. The optimal process factors and their effect on responses have been analyzed through Response Surface Methodology (RSM) and Analysis of Variance (ANOVA).

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Experimental investigation of heat and mass transfer characteristics in direct contact exchanger

Cited by 17 publications

References 22 publications

Investigation of Thermopressor with Incomplete Evaporation for Gas Turbine Intercooling Systems

Investigation of Thermopressor with Incomplete Evaporation for Gas Turbine Intercooling Systems

Numerical Simulation on Enhanced Heat Transfer and Flow Characteristics in Direct-Contact Heat Exchanger: A Novel Kenics Static Mixer

Tribological Behaviors Analysis of Synthesized Chromel Composite

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