The Experts below are selected from a list of 945 Experts worldwide ranked by ideXlab platform

Hiroaki Kiriki - One of the best experts on this subject based on the ideXlab platform.

L. K. Tartibu - One of the best experts on this subject based on the ideXlab platform.

  • Impact of Ceramic Substrates Geometry on the Performance of Simple Thermo-Acoustic Engines
    Experimental Techniques, 2018
    Co-Authors: L. K. Tartibu
    Abstract:

    This work experimentally examines the influence of the stack geometry and position on the performance of thermo-acoustic engines (TAE). Twenty cordierite Honeycomb Ceramic stacks with square pores and five different lengths (7, 13, 17, 22 and 25 mm) were considered. Measurements were taken at seven different locations of the stack hot ends from the pressure antinode (closed end), namely 52, 72, 92,112, 132, 152 and 172 mm respectively. The temperature difference across the stack and radiated sound pressure level at steady state are considered indicators of the performance of the device. The results obtained with a simple standing wave thermo-acoustic engine used in this experiment reveals that the relationships between the length, the stack pores sizes and the input power are non-linear. In addition, the effect of the viscous resistance and the thermal losses were confirmed to be strong enough when the input heating power is low.

  • A sustainable solution for refrigeration using thermo-acoustic technology (March 2016)
    2016 International Conference on the Domestic Use of Energy (DUE), 2016
    Co-Authors: L. K. Tartibu
    Abstract:

    This work explores the use of thermo-acoustic coolers as alternative technology for refrigeration. A valid experimental evidence on the influence of the geometry of the Honeycomb Ceramic stack on the performance of thermos-acoustic refrigerators is described. Sixteen cordierite Honeycomb Ceramic stacks with square cross sections having four different lengths of 26 mm, 48 mm, 70 mm and 100 mm are considered. Measurements are taken at six different locations of the stack hot ends from the pressure antinode, namely 100 mm, 200 mm, 300 mm, 400 mm, 500 mm and 600 mm respectively. Measurement of temperature difference across the stack ends at steady state for different stack geometries are used to measure the performance of the device. The results with atmospheric air demonstrates the influence of the stack geometry on the cooling power and shows that some its geometrical parameters are interdependent.

  • Maximum cooling and maximum efficiency of thermoacoustic refrigerators
    Heat and Mass Transfer, 2016
    Co-Authors: L. K. Tartibu
    Abstract:

    This work provides valid experimental evidence on the difference between design for maximum cooling and maximum efficiency for thermoacoustic refrigerators. In addition, the influence of the geometry of the Honeycomb Ceramic stack on the performance of thermoacoustic refrigerators is presented as it affects the cooling power. Sixteen cordierite Honeycomb Ceramic stacks with square cross sections having four different lengths of 26, 48, 70 and 100 mm are considered. Measurements are taken at six different locations of the stack hot ends from the pressure antinode, namely 100, 200, 300, 400, 500 and 600 mm respectively. Measurement of temperature difference across the stack ends at steady state for different stack geometries are used to compute the cooling load and the coefficient of performance. The results obtained with atmospheric air showed that there is a distinct optimum depending on the design goal.

Yongqi Liu - One of the best experts on this subject based on the ideXlab platform.

  • influence of packed Honeycomb Ceramic on heat extraction rate of packed bed embedded heat exchanger and heat transfer modes in heat transfer process
    International Communications in Heat and Mass Transfer, 2015
    Co-Authors: Zengli Gao, Yongqi Liu, Zhenqiang Gao
    Abstract:

    Abstract Under the condition that the transient oxidation heat extraction process of coal mine ventilation air methane (VAM) is equivalent to a series of steady state process, the steady state heat extraction experiment platform is built. The influence of the Honeycomb Ceramic packed in heat extraction zone and its two-side space on heat extraction rate and heat transfer modes is investigated. The experimental results show that the Honeycomb Ceramic packed in heat extraction zone two-side space can always strengthen heat extract ion of heat exchanger by increasing gas physical flow velocity in bed and radiation heat exchanging area and disturbing heat exchanger leeward side flow field. The contradictory dual characteristic of the influence of the Honeycomb Ceramic packed in heat extraction zone on heat exchanger heat extraction rate determines that the Honeycomb Ceramic has no great influence on heat extraction rate and doesn't always strengthen heat exchanger heat extraction. Contribution of heat transfer modes on packed bed embedded heat exchanger heat extraction is investigated using the method of coating heat exchanger outer surface silver; the experimental result shows that 55% contribution of packed bed embedded heat exchanger heat extraction rate is from radiation when gas mass flow rate is 0.15 kg·s − 1 ·m − 2 and its temperature is 1113 k; with the gas temperature being increased further, radiation will become the main way of packed bed embedded heat exchanger heat extraction.

  • Heat Storage Performance of a Honeycomb Ceramic Monolith
    The Open Fuels & Energy Science Journal, 2014
    Co-Authors: Yongqi Liu
    Abstract:

    Honeycomb Ceramic is the key component of the regenerative system. The three-dimensional numerical model is established which is for thermal process in Honeycomb regenerator. The numerical simulation was performed using FLUENT, a commercial computational fluid dynamics (CFD) code, to compare simulation results to the test data. The regenerative process of a Honeycomb Ceramic regenerator was simulated under different conditions. The results under different flow rates, different flowing time, different materials and different wall thickness were investigated. The work in this paper provides a theory basis and guide to the exploitation and appliance of HTAC system and the results of the numerical calculation can be used as the foundation of engineering design. The results may be utilized for design of porous media reactors and process optimization.

  • Study on Thermal Stress of Honeycomb Ceramic Regenerators with Different Parameters
    Strength of Materials, 2014
    Co-Authors: Yan Xia Wang, M. Dong, Yongqi Liu, Q. H. Shang
    Abstract:

    In thermal flow-reversal reactor operations, Honeycomb Ceramic regenerators are exposed to thermal shock load. In this study, numerical simulations of the temperature and thermal stress distributions of Honeycomb Ceramic regenerators are carried out using the CFX software. Temperature variations with time are calculated first for Honeycomb Ceramic regenerators with holes of different shapes. Then, thermal stress distributions of regenerators are analyzed with different structural and operational parameters. The analyses show that the thermal stress of Honeycomb Ceramic regenerator depends on the shape of holes, porosity and wall thicknesses. This study provides a theoretical basis for optimization of Honeycomb Ceramic regenerators.

  • heat extraction characteristic of embedded heat exchanger in Honeycomb Ceramic packed bed
    International Communications in Heat and Mass Transfer, 2012
    Co-Authors: Zengli Gao, Yongqi Liu, Zhenqiang Gao
    Abstract:

    Abstract On the basis of experimental verification of mathematical model, the influence of Honeycomb Ceramic on heat extraction is numerically studied under the steady state condition. The calculation results show the packed Honeycomb Ceramic influences the extracted heat of heat exchanger by changing the flow field while not radiation heat transfer of heat exchanger outer wall, and the difference between the extracted heat of heat exchanger embedded in packed bed and that of heat exchanger in empty bad is gradually obvious with gas temperature increasing under the condition of the same gas mass flow rate. In addition, under the same operating condition, when the two characteristic sizes of heat extraction zone Honeycomb Ceramic in the vertical gas flow direction increase, the extracted heat of embedded heat exchanger shows a trend of first increase while extracted heat of embedded heat exchanger shows a trend of decrease because the decreasing of the windward and leeward side gas flow velocity of heat exchanger results into weakening of convective heat transfer of embedded heat exchanger outer wall.

  • Simulation Research on the Resistance Characteristic of Honeycomb Ceramic Regenerator
    2010 4th International Conference on Bioinformatics and Biomedical Engineering, 2010
    Co-Authors: Yongqi Liu, Xiangchun Chen
    Abstract:

    Coal mine ventilation air methane can be mitigated by thermal oxidation in a counter-flow reactor. The pressure loss of the gas flowed in Honeycomb Ceramic which is the key component used in reverse flow reactor was studied in this paper. The mathematical model of single-channel of Ceramic Honeycomb was established by Fluent software, and the resistance characteristics of the Ceramic Honeycomb Characteristic versus the operating parameters and structure parameters of Ceramic Honeycomb were calculated. The results indicate that the greater the equivalent diameter, the smaller the resistance loss is. As the gas temperature and velocity increase, the resistance loss is increasing. This work can provide some guides for the optimization design of the counter-flow regenerative oxidation bed.

Qing Li - One of the best experts on this subject based on the ideXlab platform.

Shuichi Kubo - One of the best experts on this subject based on the ideXlab platform.