scholarly journals AN EFFECT OF SPRAY CONFIGURATION AND ADSORBENT MATERIAL ON PERFORMANCE OF THE SPRAY SCRUBBER IN THE DOWNDRAFT GASIFIER-ENGINE SYSTEM

2021 ◽  
Vol 83 (6) ◽  
pp. 167-174
Author(s):  
Anak Agung Susastriawan ◽  
Yuli Purwanto ◽  
Purnomo Purnomo ◽  
Kade Vindo ◽  
Adi Hariyanto
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Cross Flow ◽  
Small Scale ◽  
Producer Gas ◽  
Tar Removal ◽  
Downdraft Gasifier ◽  
Cooking Oil ◽  
Engine System

The work aims to investigate an effect of spray configuration and adsorbent material on performance of wet scrubber in removing tar gravimetric in producer gas. The scrubber is installed at small scale downdraft gasifier-engine system and the tests are conducted in two sections. Firstly, the scrubber is tested using water adsorbent at various spray flow configurations to the producer gas flow (cross flow, counter flow, mixed flow). Secondly, the scrubber is tested using adsorbent of cooking oil and waste of engine lubricant at cross flow spray configuration. The performance of the scrubber investigated are temperature profile, log mean temperature difference, heat transfer rate, and tar removal effectiveness. For spray configuration test, the result shows that cross spray configuration (CrS) has the optimum performance. The CsS scrubber has the highest LMTD, heat transfer rate, and tar removal efficiency among others. The values are 29.8°C, 7.84 kW, and 0.43, accordingly. Meanwhile, the test using different adsorbent indicates adsorption property of the adsorbent plays an important rules in tar removal effectiveness of the scrubber. The removal effectiveness of the scrubber for using adsorbent of water, cooking oil, and engine lubricant are 0.43, 0.12, and 0.60, respectively.

Numerical Study of Fluid Flow and Heat Transfer Enhancement of Nanofluids over Tube Bank

2013 ◽  
Vol 388 ◽  
pp. 149-155 ◽  
Author(s):  
Mazlan Abdul Wahid ◽  
Ahmad Ali Gholami ◽  
H.A. Mohammed
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Cross Flow ◽  
Bulk Temperature ◽  
Compact Heat Exchanger ◽  
Pure Fluid ◽  
Tube Banks

In the present work, laminar cross flow forced convective heat transfer of nanofluid over tube banks with various geometry under constant wall temperature condition is investigated numerically. We used nanofluid instead of pure fluid ,as external cross flow, because of its potential to increase heat transfer of system. The effect of the nanofluid on the compact heat exchanger performance was studied and compared to that of a conventional fluid.The two-dimensional steady state Navier-Stokes equations and the energy equation governing laminar incompressible flow are solved using a Finite volume method for the case of flow across an in-line bundle of tube banks as commercial compact heat exchanger. The nanofluid used was alumina-water 4% and the performance was compared with water. In this paper, the effect of parameters such as various tube shapes ( flat, circle, elliptic), and heat transfer comparison between nanofluid and pure fluid is studied. Temperature profile, heat transfer coefficient and pressure profile were obtained from the simulations and the performance was discussed in terms of heat transfer rate and performance index. Results indicated enhanced performance in the use of a nanofluid, and slight penalty in pressure drop. The increase in Reynolds number caused an increase in the heat transfer rate and a decrease in the overall bulk temperature of the cold fluid. The results show that, for a given heat duty, a mas flow rate required of the nanofluid is lower than that of water causing lower pressure drop. Consequently, smaller equipment and less pumping power are required.

scholarly journals Experimental Study for Counter to Cross Flow Air Cooled Heat Exchanger in Concentric Tube using Rectangular Copper Fins Spacing with Internal Spiral Grooving

2021 ◽  
pp. 203-208
Author(s):  
Rakesh Kumar Tiwari ◽  
Ajay Singh ◽  
Parag Mishra
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Natural Convection ◽  
Heat Exchanger ◽  
Forced Convection ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Cross Flow ◽  
Variable Number ◽  
Air Cooled Heat Exchanger

In this manuscript we have presented eight variation of Air-Cooled Heat Exchanger (ACHE) design with internal spiral grooving, all of them are having variable number of rectangular copper fins with different distances between the fins. In the proposed design we get the value of heat transfer rate of a counter to cross flow ACHE is 7833.77 watt, 4068.13 watt, 2736.95 watt, 2161.49 watt, 1802.89 watt, 1546.44 watt, 1336.51 watt and 1165.74 watt in natural convection (without fan) for 0.5 cm, 1.0 cm, 1.5 cm, 2.0 cm, 2.5 cm, 3.0 cm, 3.5 cm and 4.0 cm respectively. Then again, value of rate of heat transfer in forced convection (with fan) are 8007.46 watt, 4084.81 watt, 2754.69 watt, 2205.98 watt, 1809.24 watt, 1555.39 watt, 1352.88 watt and 1172.78 watt for 0.5 cm, 1.0 cm, 1.5cm, 2.0 cm, 2.5 cm, 3.0 cm, 3.5 cm and 4.0 cm respectively.

scholarly journals Analytical Performance Analysis of Cross Flow Louvered Fin Automobile Radiator

2018 ◽  
Vol 172 ◽  
pp. 02003
Author(s):  
R Badgujar Pankaj ◽  
S Rangarajan ◽  
S. R Nagaraja
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Cross Flow ◽  
Maximum Deviation ◽  
Side Pressure ◽  
Proposed Model ◽  
Louvered Fin ◽  
Louvered Fins

The objective of the present paper is to propose an analytical model for calculating performance parameter of a radiator having rectangular tube with louvered fins. The theoretical effectiveness, heat transfer rate, outlet temperatures of both air and coolant are determined using effectiveness-NTU method. The coolant and air side pressure drop is also calculated. The proposed procedure is validated with experimetal results available in the literature and the GT model. It is found that the maximum deviation in the heat transfer rate calculated from proposed model is 10.97%, the coolant and air outlet temperatures is 2.75% and variation in pressure drop is about 3.29%.

The Performance of a Scaled-Down Fluidized Loop Seal

2003 ◽  
Author(s):  
Andreas Johansson ◽  
Filip Johnsson ◽  
Bengt-A˚ke Andersson
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Scaling Laws ◽  
Tube Bundle ◽  
Flow Behavior ◽  
Cross Flow ◽  
Operating Conditions ◽  
Cfb Boiler ◽  
Super Heater

This work investigates the solids cross flow in a super-heater tube bundle immersed in the loop seal of a cold CFB unit. The loop seal and the tube bundle are scaled to a 1/3rd of the size of a loop seal and a super-heater located in a 30 MWth CFB boiler. The simplified scaling laws proposed by Glicksman et al. [1] are applied to the flow in the seal. The loop seal was built into an existing CFB unit with riser dimensions 0.7 m × 0.12 m × 8.5 m. The riser is not scaled but the pressure distribution in the CFB loop is similar to that in the boiler. The solids flow through the tube bundle was studied by means of visual observations, pressure drop and tube-temperatures, corresponding to the overall heat transfer rate to each tube. The loop seal was operated under various conditions, including those typical for the boiler. Thus, the recirculation flux of solids through the loop seal, as well as the fluidization velocity in the seal, were varied. In addition, the fraction of the bottom area that is fluidized was varied. The overall flow behavior of the CFB loop with the scaled loop seal was found to be similar to that of the boiler. The temperature measurements showed that the heat transfer rate to the tubes in the bundle differed depending on operating conditions and on the position of the tube, both laterally and vertically. The recirculation flux could be maintained with a substantial decrease of the fluidization flow in the seal compared to the conditions corresponding to full load in the boiler. In addition, it was possible to significantly decrease the fraction of the bottom of the seal that was fluidized. However, if the area beneath the tube bundle is not fluidized, the heat transfer rate to the tubes decreased.

Thermal Efficiency of the Cross Flow Heat Exchangers

2006 ◽  
Author(s):  
Ahmad Fakheri
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Transfer Rate ◽  
Heat Exchangers ◽  
Transfer Rate ◽  
Cross Flow ◽  
Algebraic Expression ◽  
Counter Flow ◽  
Optimum Heat ◽  
Flow Heat

The heat exchanger efficiency is defined as the ratio of the actual heat transfer in a heat exchanger to the optimum heat transfer rate. The optimum heat transfer rate, qopt, is given by the product of UA and the Arithmetic Mean Temperature Difference, which is the difference between the average temperatures of hot and cold fluids. The actual rate of heat transfer in a heat exchanger is always less than this optimum value, which takes place in an ideal balanced counter flow heat exchanger. It has been shown that for parallel flow, counter flow, and shell and tube heat exchanger the efficiency is only a function of a single nondimensional parameter called Fin Analogy Number. The function defining the efficiency of these heat exchangers is identical to that of a constant area fin with an insulated tip. This paper presents exact expressions for the efficiencies of the different cross flow heat exchangers. It is shown that by generalizing the definition of Fa, very accurate results can be obtained by using the same algebraic expression, or a single algebraic expression can be used to assess the performance of a variety of commonly used heat exchangers.

scholarly journals Thermal Behavior of Aerogel-Embedded Nonwovens in Cross Airflow

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Xiaoman Xiong ◽  
Mohanapriya Venkataraman ◽  
Darina Jašíková ◽  
Tao Yang ◽  
Rajesh Mishra ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Convective Heat Transfer Coefficient ◽  
Cross Flow ◽  
Continuous Heating ◽  
Measuring Device ◽  
Nonwoven Fabrics ◽  
Good Ability

AbstractThermal performance of aerogel-embedded polyester/polyethylene nonwoven fabrics in cross airflow was experimentally studied by using a laboratory-built dynamic heat transfer measuring device in which the fabric could be applied on a heating rod. Experiments were performed with different airflow velocities and heating conditions. The temperature–time histories of different materials were collected and compared. The temperature difference and convective heat transfer coefficient under continuous heating were analyzed and discussed. Results showed that under preheated conditions, the aerogel-embedded nonwoven fabrics had very small decrease in temperature and good ability to prevent against heat loss in cross flow. As for the continuous heating conditions, the heat transfer rate of each material showed an increasing trend with increase in the Reynolds number. The aerogel-treated nonwoven fabric with the least fabric thickness and aerogel content delivered a significantly increased heat transfer rate at higher Reynolds number. Thicker fabrics with higher aerogel content could provide better insulation ability in cross flow.

scholarly journals Experimental Study of Counter to Cross Flow Air-Cooled Heat Exchanger using different Fins pitch with Internal Circular Grooving

2021 ◽  
pp. 197-202
Author(s):  
Rishi Kumar ◽  
Parag Mishra ◽  
Ajay Singh
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Heat Exchanger ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Cross Flow ◽  
Variable Number ◽  
The Other ◽  
Air Cooled Heat Exchanger ◽  
Annular Tube

In this manuscript we have presented seven variation of Air-Cooled Heat Exchanger (ACHE) design with internal grooving annular tube, all of them are having variable number of aluminum rectangular fins with different distances between the fins. In the proposed design we get the value of heat transfer rate of a counter to cross flow ACHE is 7062.95 watt, 3969.78 watt, 2724.15 watt, 2149.25 watt, 1785.03 watt, 1533.43 watt, and 1325.34 watt in natural convection (without fan) for 5 mm, 10 mm, 15mm, 20 mm, 25 mm, 30 mm and 35 mm respectively. On the other hand the value of heat transfer rate in forced convection (with fan) are 7100.40 watt, 3995.30 watt, 2740.54 watt, 2162.26 watt, 17897.63 watt, 1540.00 watt, and 1331.60 watt for 5 mm, 10 mm, 15mm, 20 mm, 25 mm, 30 mm and 35 mm respectively.

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