Experimental Analysis of Heat Transfer From Ice Rink Floors

Solar Energy ◽  
2006 ◽  
Author(s):  
Jung Mun ◽  
Moncef Krarti
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Thermal Insulation ◽  
Air Temperature ◽  
Experimental Analysis ◽  
Experimental Results ◽  
Water Ice ◽  
Set Up ◽  
Time Required ◽  
The Impact

This paper describes an experimental set-up to evaluate the refrigeration loads for ice rink floors under controlled conditions. The ice-rink set-up was instrumented to measure the temperatures along various locations within the ice-rink floor including the water/ice layer. In addition, the energy used to freeze the water is monitored over the entire charging cycle to evaluate the performance of the ice rink floor for various insulation thermal resistance values (or R-values). Four floor insulation configurations are considered in the experimental analysis of R-0 (no insulation), R-4.2, R-6.7 and R-10 (in IP unit: hr.ft2.°F/Btu). The impact of the air temperature above the ice rink is also evaluated. The experimental results confirm that the addition of the thermal insulation beneath the ice-rink floor reduces the refrigeration load, decreased the time required to freeze the water above the ice rink, and helps maintain lower average ice temperature.

scholarly journals Appraising the Impacts of Globalization on Gravity Model Economic Systems

2019 ◽  
Vol 5 (09) ◽  
Author(s):  
Dr. Bilal Khlaf Al Omari
Keyword(s):  
Latent Variable ◽  
Bilateral Trade ◽  
Trade Flow ◽  
Trade Agreements ◽  
Economic Systems ◽  
General Hypothesis ◽  
The World ◽  
Set Up ◽  
Time Required ◽  
The Impact

This study aims at exploring the impact of economic globalization factors on the gravity economic systems. Nonetheless, the basis of the research is a gravity economic system exposed to the impacts of globalization, and the concern is to explore the effects of the exposure on the influences of distance and economic sizes on the model. Recognizing the role of population growth and globalization in driving bilateral trade follows is one of the objectives of this research as should be part of an economic model. The study used the modified gravity and globalization variables, data retrieved from the CEPII, the World Fact-book, and the World Bank. The ordinary squares regression and STATA statistical software were used to investigate the hypotheses. The model leading to the general hypothesis that globalization is reducing the cost of entry, and total time required to set up a business and to minimize the bureaucracy associated with registering businesses and launching operations. The trade flow latent variable should contain information on export, import, free trade agreements, preferential trade agreements, and union memberships, which would help in identifying globalization factors that mediate the interaction between global variables and bilateral trade responses.

scholarly journals Research and Improvement of the Hydraulic Suspension System for a Heavy Hydraulic Transport Vehicle

2020 ◽  
Vol 10 (15) ◽  
pp. 5220 ◽  
Author(s):  
Jianjun Wang ◽  
Jingyi Zhao ◽  
Wenlei Li ◽  
Xing Jia ◽  
Peng Wei
Keyword(s):  
Mathematical Model ◽  
Nonlinear System ◽  
Ride Comfort ◽  
Impact Force ◽  
Suspension System ◽  
Experimental Results ◽  
Hydraulic Transport ◽  
Transport Vehicle ◽  
Set Up ◽  
The Impact

In order to ensure the ride comfort of a hydraulic transport vehicle in transportation, it is important to account for the effects of the suspension system. In this paper, an improved hydraulic suspension system based on a reasonable setting of the accumulator was proposed for a heavy hydraulic transport vehicle. The hydraulic transport vehicle was a multi-degree nonlinear system, and the establishment of an appropriate vehicle dynamical model was the basis for the improvement of the hydraulic suspension system. The hydraulic suspension system was analyzed, and a mathematical model of the hydraulic suspension system with accumulator established and then analyzed. The results revealed that installing the appropriate accumulator can absorb the impact pressure on the vehicle, while a hydraulic suspension system with an accumulator can be designed. Further, it was proved that a reasonable setting for the accumulator can reduce the impact force on the transport vehicle through simulation, and the optimal accumulator parameters can be obtained. Finally, an experiment in the field was set up and carried out, and the experimental results presented to prove the viability of the proposed method.

scholarly journals Change in Conductive–Radiative Heat Transfer Mechanism Forced by Graphite Microfiller in Expanded Polystyrene Thermal Insulation—Experimental and Simulated Investigations

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2626
Author(s):  
Aurelia Blazejczyk ◽  
Cezariusz Jastrzebski ◽  
Michał Wierzbicki
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Thermal Resistance ◽  
Thermal Insulation ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Expanded Polystyrene ◽  
Transfer Mechanism ◽  
Total Thermal Conductivity ◽  
Heat Transfer Mechanism

This article introduces an innovative approach to the investigation of the conductive–radiative heat transfer mechanism in expanded polystyrene (EPS) thermal insulation at negligible convection. Closed-cell EPS foam (bulk density 14–17 kg·m−3) in the form of panels (of thickness 0.02–0.18 m) was tested with 1–15 µm graphite microparticles (GMP) at two different industrial concentrations (up to 4.3% of the EPS mass). A heat flow meter (HFM) was found to be precise enough to observe all thermal effects under study: the dependence of the total thermal conductivity on thickness, density, and GMP content, as well as the thermal resistance relative gain. An alternative explanation of the total thermal conductivity “thickness effect” is proposed. The conductive–radiative components of the total thermal conductivity were separated, by comparing measured (with and without Al-foil) and simulated (i.e., calculated based on data reported in the literature) results. This helps to elucidate why a small addition of GMP (below 4.3%) forces such an evident drop in total thermal conductivity, down to 0.03 W·m−1·K−1. As proposed, a physical cause is related to the change in mechanism of the heat transfer by conduction and radiation. The main accomplishment is discovering that the change forced by GMP in the polymer matrix thermal conduction may dominate the radiation change. Hence, the matrix conduction component change is considered to be the major cause of the observed drop in total thermal conductivity of EPS insulation. At the microscopic level of the molecules or chains (e.g., in polymers), significant differences observed in the intensity of Raman spectra and in the glass transition temperature increase on differential scanning calorimetry(DSC) thermograms, when comparing EPS foam with and without GMP, complementarily support the above statement. An additional practical achievement is finding the maximum thickness at which one may reduce the “grey” EPS insulating layer, with respect to “dotted” EPS at a required level of thermal resistance. In the case of the thickest (0.30 m) panels for a passive building, above 18% of thickness reduction is found to be possible.

scholarly journals The Influence of Different Facings of Polyisocyanurate Boards on Heat Transfer through the Wall Corners of Insulated Buildings

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1991 ◽  
Author(s):  
Tomas Makaveckas ◽  
Raimondas Bliūdžius ◽  
Arūnas Burlingis
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Flux ◽  
Thermal Insulation ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Thermal Bridge ◽  
Thermal Bridges ◽  
The Impact ◽  
Heat Flow Meter

Polyisocyanurate (PIR) thermal insulation boards faced with carboard, plastic, aluminum, or multilayer facings are used for thermal insulation of buildings. Facing materials are selected according to the conditions of use of PIR products. At the corners of the building where these products are joined, facings can be in the direction of the heat flux movement and significantly increase heat transfer through the linear thermal bridge formed in the connection of PIR boards with facing of both walls. Analyzing the installation of PIR thermal insulation products on the walls of a building, the structural schemes of linear thermal bridges were created, numerical calculations of the heat transfer coefficients of the linear thermal bridges were performed, and the influence of various facings on the heat transfer through the thermal bridge was evaluated. Furthermore, an experimental measurement using a heat flow meter apparatus was performed in order to confirm the results obtained by numerical calculation. This study provides more understanding concerning the necessity to evaluate the impact of different thermal conductivity facings on the heat transfer through corners of buildings insulated with PIR boards.

scholarly journals Impact of convection on thermographic analysis of silver based thermal joints

2020 ◽  
Vol 32 (4) ◽  
pp. 241-246
Author(s):  
Krzysztof Jakub Stojek ◽  
Jan Felba ◽  
Johann Nicolics ◽  
Dominik Wołczyński
Keyword(s):  
Heat Transfer ◽  
Thermal Analysis ◽  
Energy Loss ◽  
Thermal Resistance ◽  
Analysis Method ◽  
Content Type ◽  
Heat Transfer Efficiency ◽  
Lowered Pressure ◽  
Thermographic Analysis ◽  
The Impact

Purpose This paper aims to develop thermal analysis method of thermal joints characterization. The impact on convection on thermal resistance analysis with use thermography for silver-based thermal joints were investigated for non-metallized and metalized semiconductor surfaces. Heat transfer efficiency depends on thermal conductivity; radiation was used to perform thermographic analysis; the convection is energy loss, so its removing might improve measurements accuracy. Design/methodology/approach Investigation of thermal joints analysis method was focused on determination of convection impact on thermal resistance thermographic analysis method. Measuring samples placed in vacuum chamber with lowered pressure requires transparent window for infrared radiation that is used for thermographic analysis. Impact of infrared window and convection on temperature measurements and thermal resistance were referred. Findings The results showed that the silicon window allowed to perform thermal analysis through, and the convection was heat transfer mode which create 15% energy loss. Originality/value It is possible to measure thermal resistance for silver-based thermal joints with convection eliminated to improve measurements accuracy.

A Simple Thermal Resistance Model for Open Cell Metal Foams

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Pradeep. M. Kamath ◽  
C. Balaji ◽  
S. P. Venkateshan
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Contact Resistance ◽  
Convective Heat Transfer Coefficient ◽  
Vertical Channel ◽  
Metal Foams ◽  
Experimental Results ◽  
Actual Case ◽  
Open Cell ◽  
Resistance Model

This paper presents a methodology for obtaining the convective heat transfer coefficient from the wall of a heated aluminium plate, placed in a vertical channel filled with open cell metal foams. For accomplishing this, a thermal resistance model from literature for metal foams is suitably modified to account for contact resistance. The contact resistance is then evaluated using the experimental results. A correlation for the estimation of the contact resistance as a function of the pertinent parameters, based on the above approach is developed. The model is first validated with experimental results in literature for the asymptotic case of negligible contact resistance. A parametric study of the effect of different foam parameters on the heat transfer is reported with and without the presence of contact resistance. The significance of the effect of contact resistance in the mixed convection and forced convection regimes is discussed. The procedure to employ the present methodology in an actual case is demonstrated and verified with additional, independent experimental data.

The Effect of Thermal Barrier Coating Surface Temperature on the Adhesion Behavior of CMAS Deposits

2020 ◽  
Author(s):  
Robert A. Clark ◽  
Nicholas Plewacki ◽  
Pritheesh Gnanaselvam ◽  
Jeffrey P. Bons ◽  
Vaishak Viswanathan
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Surface Temperature ◽  
Mass Flow ◽  
Experimental Results ◽  
Thermal Barrier ◽  
Back Side ◽  
Surface Temperatures ◽  
The Impact ◽  
Side Flow

Abstract The interaction of thermal barrier coating’s surface temperature with CMAS (calcium magnesium aluminosilicate) like deposits in gas turbine hot flowpath hardware is investigated. Small Hastelloy X coupons were coated in TBC using the air plasma spray (APS) method and then subjected to a thermal gradient via back-side impingement cooling and front-side impingement heating using the High Temperature Deposition Facility (HTDF) at The Ohio State University (OSU). A 1-D heat transfer model was used to estimate TBC surface temperatures and correlate them to intensity values taken from infrared (IR) images of the TBC surface. TBC frontside surface temperatures were varied by changing back-side mass flow (kept at a constant temperature), while maintaining a constant hot-side gas temperature and jet velocity representative of modern commercial turbofan high-pressure turbine (HPT) inlet conditions (approximately 1600K and 200 m/s, or Mach 0.25). In this study, Arizona Road Dust (ARD) was utilized to mimic the behavior of CMAS attack on TBCs. To identify the minimum temperature at which particles adhere, the back-side cooling mass flow was set to the maximum amount allowed by the test setup, and trace amounts of 0–10 μm ARD particles were injected into the hot-side flow to impinge on the TBC surface. The TBC surface temperature was increased through coolant reduction until noticeable deposits formed, as evaluated through an IR camera. Accelerated deposition tests were then performed where approximately 1 gram of ARD was injected into the hot side flow while the TBC surface temperature was held at various points above the minimum observed deposition temperature. Surface deposition on the TBC coupons was evaluated using an infrared camera and a backside thermocouple. Coupon cross sections were also evaluated under a scanning electron microscope for any potential CMAS ingress into the TBC. Experimental results of the impact of surface temperature on CMAS deposition and deposit evolution and morphology are presented. In addition, an Eulerian-Lagrangian solver was used to model the hot-side impinging jet with particles at four TBC surface temperatures and deposition was predicted using the OSU Deposition model. Comparisons to experimental results highlight the need for more sophisticated modeling of deposit development through conjugate heat transfer and mesh morphing of the target surface. These results can be used to improve physics-based deposition models by providing valuable data relative to CMAS deposition characteristics on TBC surfaces, which modern commercial turbofan high pressure turbines use almost exclusively.

Optimization of Pass Design of Bidirectional Thermal-Insulation Bricks

2014 ◽  
Vol 1008-1009 ◽  
pp. 1348-1351
Author(s):  
Sha Sha Dong ◽  
Xiao Ping Feng
Keyword(s):  
Thermal Conductivity ◽  
Thermal Resistance ◽  
Thermal Insulation ◽  
Thermal Performance ◽  
Element Model ◽  
Two Dimensional ◽  
Pass Design ◽  
Dimensional Finite Element ◽  
The Impact ◽  
Better Than

The thermal performance of perforated brick is affected by various factors, thermal conductivity, the holes rates, the pass design and etc. included. In order to analyze the impact of the pass design on the thermal performance of bidirectional thermal insulation bricks, the two-dimensional finite element model was developed using ANSYS. The simulated result shows that existence of vertical holes can enhance the thermal resistance in the longer dimension of the perforated brick. Under the condition of the same holes rates, narrowing the width of the vertical holes helps to improve the thermal resistance in the shorter dimension of the perforated brick. The function of these blocks are extremely influenced by the distribution of the vertical holes, the concentrated better than the both-sided when it comes to advancing the whole function.

Heat Transfer in an LTV Falling Film Evaporator: A Theoretical and Experimental Analysis

1968 ◽  
Vol 90 (2) ◽  
pp. 201-210 ◽  
Author(s):  
J. E. Kroll ◽  
J. W. McCutchan
Keyword(s):  
Heat Transfer ◽  
Mathematical Models ◽  
Flow Rate ◽  
Experimental Analysis ◽  
Experimental Results ◽  
Falling Film ◽  
Film Evaporator ◽  
Good Agreement

Two slightly differing mathematical models were developed to describe the heat transfer in the long tube vertical falling film process. The process was investigated experimentally with a 3/4 in. dia tube for various lengths up to 13 ft, for flow rate Reynold’s numbers from 1000 to 13000, for temperature differences of the order of 20 deg F, and for vacuum conditions down to 160 deg F. A comparison of theoretical and experimental results was made and was found to be in good agreement; that is, within 10 percent.

PROCESSED STRAW AS EFFECTIVE THERMAL INSULATION FOR BUILDING ENVELOPE CONSTRUCTIONS

2012 ◽  
Vol 4 (3) ◽  
pp. 96-103 ◽  
Author(s):  
Jolanta Vėjelienė
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Building Envelope ◽  
Gas Content ◽  
Barley Straw ◽  
Conductivity Measurements ◽  
Insulation Materials ◽  
Thermal Transfer ◽  
The Impact

The efficiency of thermal insulation materials obtained from renewable resources depends on the possibilities of reducing thermal transfer via solid and gaseous conduction, thermal radiation and, in some cases, convection. The heat transfer mechanism for thermal insulation materials mostly depends on the structure and density of the material used. Efficient thermal insulation materials consist of a gaseous phase and a solid skeleton. Gas content in such materials can take more than 99% of material by volume. In this case, thermal transfer via solid conductivity is negligible. The current work analyses the possibilities of reducing heat transfer in the straw of a varying structure. For conducting experiments, barley straw was used. To evaluate the impact of straw stalk orientation in a specimen on thermal conductivity, strongly horizontally and vertically oriented specimens of straw stalks were prepared. To reduce heat transfer via gaseous conduction and convection in large cavities in straw stalks and between stalks, barley straw were chopped and defibered. In order to decrease heat transfer via radiation after thermal conductivity measurements, mechanically processed straw were coated with infrared absorbers. Due to thermal conductivity measurements of chopped and defibered straw, an optimal amount of infrared absorbers were determined.

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