scholarly journals Study on Selection of a Suitable Material and The Parameters for Designing a Portable Flat Plate Base-Thermal Cell Absorber (FPBTCA)

2021 ◽  
Vol 85 (1) ◽  
pp. 71-92
Author(s):  
Muhammad Amin Harun ◽  
Zafri Azran Abdul Majid ◽  
Zairul Azrul Zakaria ◽  
Ahmad Faris Ismail ◽  
Sany Izan Ihsan ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Flat Plate ◽  
High Heat ◽  
Air Gap ◽  
Absorber Thickness ◽  
Heat Gain ◽  
Glass Thickness ◽  
Gain Rate ◽  
Thermal Cell ◽  
Plate Absorber

Several types of flat plate solar collectors have been designed and developed with various technical parameters involved in the design. The inappropriate flat plate solar collector parameter design and material chosen will affect its performance. Investigation on the effect of flat plate absorber collector material, glass thickness, air gap distance, thermal cell absorber thickness, and flat plate absorber base collector thickness on the performance of solar thermal collectors was conducted in this work. The experiment was performed using the solar simulator with solar radiation of 450 and 750 W/m2. The flat plate absorber collector materials used in this experiment were stainless steel 304 and aluminum. The glass thickness used in this experiment was 2.0, 3.0, 4.0, 5.0, and 10.0 mm. The air gap between the flat plate absorber and glass used in this experiment was 0, 5.0, 10.0, 20.0, and 30.0 mm. The stainless steel thermal cell absorber thickness applied in this experiment was 0.5, 1.0, and 2.0 mm. Meanwhile, the aluminum flat plate base absorber base collector thickness was 0.5, 0.8, and 1.0 mm. The results showed that the 2.0 mm glass thickness has the maximum flat plate absorber temperature (88.1 oC at t = 600 s), high heat gain rate (0.097 oC/s), and the highest total heat gain (1207.33 J). The results also revealed that the air gap distance of 10 mm achieved the maximum flat plate absorber temperature (64.6 oC at t = 600 s), the highest heat gain rate (0.058 oC/s), and the highest total heat gain (4750.92 J). The stainless steel thermal cell absorber thickness of 1.0 mm has the thermal cell absorber temperature of 76.2 oC at t = 600 s and a high heat gain rate at 0.08 oC/s. The aluminum flat plate base absorber achieved the highest flat plate absorber temperature (67.2 oC at t = 600 s) and the highest heat gain rate (0.062 oC/s). By using double glass as glass cover increase the flat plate absorber temperature (76.3 oC at t = 600 s) and the highest heat gain rate (0.077 oC/s). This research aims to produce a flat plate absorber with better energy storage, i.e., the performance of the stainless steel plate absorber is better than aluminum with the same thickness. Although the stainless steel flat plate absorber collector showed a lower temperature than aluminum, it has a higher temperature drop than the latter.

FLAT PLATE PULSATING HEAT PIPES WITH DIFFERENT CHANNEL GEOMETRIES FOR HIGH HEAT FLUX APPLICATIONS

2020 ◽  
Author(s):  
Larissa Krambeck ◽  
Kelvin Guessi Domiciano ◽  
Luis Alonso Betancur Arboleda ◽  
Marcia Mantelli
Keyword(s):  
Heat Flux ◽  
Flat Plate ◽  
Heat Pipes ◽  
High Heat ◽  
High Heat Flux

Reducing Roof Solar Heat Gain by Using Double-Skin Ventilated Roofs

2020 ◽  
Vol 38 (3A) ◽  
pp. 402-411
Author(s):  
Mohannad R. Ghanim ◽  
Sabah T. Ahmed
Keyword(s):  
Inclination Angle ◽  
Convection Heat Transfer ◽  
Ventilation Rate ◽  
Channel Length ◽  
Air Gap ◽  
Galvanized Steel ◽  
Heat Gain ◽  
Solar Heat ◽  
Double Skin ◽  
Solar Heat Gain

Double skin ventilated roof is one of the important passive cooling techniques to reduce solar heat gain through roofs. In this research, an experimental study was performed to investigate the thermal behaviour of a double skin roof model. The model was made of two parallel galvanized steel plates. Galvanized steel has been used in the roof construction of industrial buildings and storehouses in Iraq. The effect of inclination angle (ϴ) from the horizontal and the spacing (S) between the plates was investigated at different radiation intensities. It is found that using a double skin roof arrangement with a sufficient air gap (S) can reduce the heat gain significantly. The higher the inclination angle (ϴ) the higher the ventilation rate, the lower the heat gain through the roof. In this study, increasing the air gap from 2 cm to 4 cm reduced the heat gain significantly but when the gap was further increased to 6 cm, the reduction in the heat flux was insignificant. A dimensionless correlation was also reduced between Nusselt number () and the single parameter  where L is the channel length. This correlation can be handily utilized for designing of engineering applications dealing with high temperature difference natural convection heat transfer.

ARMCO 25-12

Alloy Digest ◽  
1955 ◽  
Vol 4 (7) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
High Strength ◽  
Heat Treating ◽  
High Heat ◽  
Temperature Performance ◽  
Aisi Type ◽  
Lower Carbon

Abstract ARMCO 25-12 is an austenitic chromium-nickel stainless steel with high heat resisting qualities, high strength and creep values up to 2000 F. It is equivalent to AISI Type 309 stainless steel; and in the lower carbon grade is equivalent to AISI Type 309S. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness, creep, and fatigue. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-32. Producer or source: Armco Inc., Eastern Steel Division.

scholarly journals Higher Order Accurate Transient Numerical Model to Evaluate the Natural Convection Heat Transfer in Flat Plate Solar Collector

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1508
Author(s):  
Nagesh Babu Balam ◽  
Tabish Alam ◽  
Akhilesh Gupta ◽  
Paolo Blecich
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Flat Plate ◽  
Solar Collector ◽  
Convection Heat Transfer ◽  
Air Gap ◽  
Convection Flow ◽  
Natural Convection Heat Transfer ◽  
Convection Heat ◽  
Flat Plate Solar Collector

The natural convection flow in the air gap between the absorber plate and glass cover of the flat plate solar collectors is predominantly evaluated based on the lumped capacitance method, which does not consider the spatial temperature gradients. With the recent advancements in the field of computational fluid dynamics, it became possible to study the natural convection heat transfer in the air gap of solar collectors with spatially resolved temperature gradients in the laminar regime. However, due to the relatively large temperature gradient in this air gap, the natural convection heat transfer lies in either the transitional regime or in the turbulent regime. This requires a very high grid density and a large convergence time for existing CFD methods. Higher order numerical methods are found to be effective for resolving turbulent flow phenomenon. Here we develop a non-dimensional transient numerical model for resolving the turbulent natural convection heat transfer in the air gap of a flat plate solar collector, which is fourth order accurate in both spatial and temporal domains. The developed model is validated against benchmark results available in the literature. An error of less than 5% is observed for the top heat loss coefficient parameter of the flat plate solar collector. Transient flow characteristics and various stages of natural convection flow development have been discussed. In addition, it was observed that the occurrence of flow mode transitions have a significant effect on the overall natural convection heat transfer.

Research on 304,321,316Lect. Stainless Steel Corrosion under the Calcinating Gas Atmosphere of Ammonium Paramolybdate

2012 ◽  
Vol 602-604 ◽  
pp. 421-425 ◽  
Author(s):  
Chang Sen Luo ◽  
Hong Luo ◽  
Xi Yang He
Keyword(s):  
Stainless Steel ◽  
Weight Gain ◽  
Average Rate ◽  
Steel Corrosion ◽  
Corrosion Layer ◽  
Surface Phase ◽  
Phase Constituent ◽  
Gain Rate ◽  
Gas Atmosphere ◽  
Weight Gain Rate

In this paper, the corrosion behavior was researched which was happen on the 304,321,316Lect. stainless steel materials in the analogue situation of calcining gas atmosphere of ammonium paramolybdate.The oxidized etch which happened on the sample’s surface, phase constituent and element content of the fracture surface, was analyzed by the means of SEM、XRD.The results showed that the phases of Fe2(MoO4)3,MoO3,MoO2.5(OH)0.5,Cr2O3,Cr2Ti5O13, Fe2O3,Fe3O4 ect. are contained on the surfaces of the 304,316L, 321 samples which are calcined. There is an inside oxidized corrosion layer in 304 316L. The oxidizing film is damaged and the oxygen penetrates into the base to form an oxidized layer. A thin and compact oxidation film was formed between 321 corrosion layer and the alloy interface, which have prevented the base from further corrosion, under this experiment conditions, this steel belonged to the inoxidizability materials. The coating deficiency of 321 steel is shallow; the particles of oxidate is thin and without inner corrosion; the weight gain rate of oxidized etch is slow (average rate 5.2×10-2mg/ (cm2•h)), the weight gain is less and corrosion resistance is fine.

Evaluation of Strength on Dissimilar Metal Joints for ITER First Wall Components

2010 ◽  
Author(s):  
H. Nishi ◽  
M. Enoeda ◽  
T. Hirose ◽  
D. Tsuru ◽  
H. Tanigawa
Keyword(s):  
Heat Flux ◽  
Stainless Steel ◽  
Stress Singularity ◽  
Dissimilar Materials ◽  
High Heat ◽  
High Heat Flux ◽  
First Wall ◽  
Cu Alloy ◽  
Quarter Plane ◽  
Plane Joint

The first wall (FW) of ITER blanket includes beryllium (Be) armor tiles joined to CuCrZr heat sink with stainless steel cooling tube and backing plate in order to improve plasma performance and reduce thermal stress. Therefore dissimilar materials joints are indispensable for fabricating the high heat flux components. Since these joints must withstand thermal and mechanical loads caused by the plasma and electromagnetic force, it is important to evaluate the strength and thermal fatigue life of dissimilar materials joints. When the dissimilar materials joints are subjected by external force and thermal loading, the stress of the joint may indicate singularity at the interface edge. Since the stress singularity may lower the strength of joints, the singularity is evaluated numerically for the various materials combinations and joint configuration to be used in high heat flux components of fusion reactors in this investigation. Moreover, tensile test and elasto-plastic FEM analysis are performed to investigate the fracture behavior of Be/Cu alloy and stainless steel/ Cu alloy obtained the FW mock-up. The results reveal two singular solutions of type rpj−1 for a half-plane bonded to a quarter-plane joint and the singularity is larger than that of a bonded quarter-planes joint. From the viewpoint of stress singularity, the configuration of bonded quarter-planes joint is better than the half-plane bonded to a quarter-plane joint. The singularity for W/Cu alloy combination is large compared to other combination of materials. Especially the singularity of stainless steel/ Cu alloy is very small. Tensile specimen of Be/CuCrZr joint fractured at the bonding interface due to the stress singularity. For the stainless steel/ Cu alloy, however, the specimens fractured at the Cu alloy region apart from the interface.

scholarly journals Prediction of High-Cycle Fatigue Performance of 1Cr11Ni2W2MoV Stainless Steel Plate after Foreign Object Damage

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Zhenhua Zhao ◽  
Lingfeng Wang ◽  
Chao Liu ◽  
Lulu Liu ◽  
Wei Chen
Keyword(s):  
Stainless Steel ◽  
Flat Plate ◽  
Crack Growth ◽  
High Cycle Fatigue ◽  
Fatigue Cracks ◽  
Foreign Object ◽  
Cycle Fatigue ◽  
Worst Case ◽  
Foreign Object Damage ◽  
Damage Depth

High-cycle fatigue (HCF) properties of 1Cr11Ni2W2MoV stainless steel impacted by a high-speed steel ball were studied by the foreign object damage (FOD) test and HCF test. The results show that the damage depth Z has the most obvious effect on the HCF limit of notched flat plate specimens, and the fatigue limit decreases with the increase of depth Z . The microcharacteristics of the FOD notch and HCF fracture of 1Cr11Ni2W2MoV stainless steel were observed by a scanning electron microscope (SEM). The results show that the microdamage features such as plastic deformation, loss of material, and microcracks promote the initiation and propagation of fatigue cracks, and the fatigue source area lies near the root of the notch. The Peterson formula and Worst Case Notch (WCN) mode were used to predict the HCF limit of flat plate specimens after FOD. The crack growth threshold was obtained by the crack growth test. The results show that the prediction results of both methods are conservative. For the notch with damage depth Z < 1  mm, the prediction accuracy of the WCN model is higher ( error   range < 30 % ). For the notch with damage depth Z > 1  mm, the prediction results of both methods have large errors (>30%) with the WCN model being slightly more accurate.

CASS Fracture Tests Using Flat Plate Specimens With a Surface Flaw

2015 ◽  
Author(s):  
Kiminobu Hojo ◽  
Wataru Nishi ◽  
Shotaro Hayashi
Keyword(s):  
Stainless Steel ◽  
Flat Plate ◽  
Thermal Aging ◽  
Limit Load ◽  
Surface Flaw ◽  
Tensile Fracture ◽  
Ferrite Number ◽  
Fracture Tests ◽  
Depth Curve ◽  
Two Parameter

JSME rules for fitness for service have flaw acceptance rules for cast austenitic stainless steel (CASS) pipes. They allow applying two-parameter and elastic-plastic fracture mechanics methods using Z-factor. However they do not clearly describe whether limit load method is applicable for the case of no or low thermal aging condition. The authors performed tensile fracture tests using flat plate specimens with a surface flaw and confirmed that limit load method is applicable in the conditions of no thermal aging and even fully saturated thermal aging with high ferrite number. Also the plate with a shallow flaw ruptured at the critical stress defined by nominal stress at rupture-flaw depth curve in the code case which was determined by the similar flat plate tests of stainless steel or nickel alloy specimens. These results will be reflected to the revision of the code.

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