The latent heat recovery from boiler exhaust flue gas using shell and corrugated tube heat exchanger: A numerical study

Heat Transfer ◽  
2020 ◽  
Vol 49 (6) ◽  
pp. 3797-3815 ◽  
Author(s):  
Sharare Mohammadi ◽  
Seyed Soheil Mousavi Ajarostaghi ◽  
Mohsen Pourfallah
Keyword(s):  
Heat Exchanger ◽  
Latent Heat ◽  
Flue Gas ◽  
Heat Recovery ◽  
Numerical Study ◽  
Tube Heat Exchanger ◽  
Corrugated Tube

Thermal-Hydraulic Behavior and Prediction of Heat Exchanger for Latent Heat Recovery of Exhaust Flue Gas

1999 ◽  
Author(s):  
Masahiro Osakabe
Keyword(s):  
Heat Exchanger ◽  
Latent Heat ◽  
Flow Rate ◽  
Flue Gas ◽  
Heat Exchangers ◽  
Pressure Loss ◽  
Heat Recovery ◽  
Finned Tubes ◽  
Temperature Distributions ◽  
Inner Diameter

Abstract In order to improve the boiler efficiency, latent heat recovery from the flue gas is very important concept. Three kinds of countercurrent cross-flow heat exchangers, which consist of bare tubes, spirally finned tubes of fin pitch 5 and 10mm, were designed and used for the experiment. The heat exchanger of the bare tubes consists of a staggered bank of 5-4 rows and 50 stages. The length, outer and inner diameter of the bare tube is 482, 27.2 and 23.2mm, respectively. The heat exchangers of finned tubes consist of staggered banks of 3-2 rows, 34 stages for the fin pitch 10mm and 20 stages for the pitch 5mm. The length, outer and inner diameter of the base tube welded with the fins is 482, 34 and 28.8mm, respectively. The thickness and height of the plate fin are 1 and 12mm, respectively. The parametric study varying the flue gas flow rate, feed water temperature and flow rate was conducted. The temperature distributions of water and flue gas in the heat exchanger were measured with sheath K-type thermocouples of 1.6 mm in diameter. The pressure loss and the total amount of condensate generated in the heat exchanger were also measured. Based on the previous basic studies, a prediction method for the heat exchanger was proposed. In the prediction, the flue gas was treated as a mixture of CO2, CO, O2, N2 and H2O, and the one-dimensional heat and mass balance calculation along the flow direction of flue gas was conducted. The heat and mass transfer on tubes was evaluated with a simple analogy correlation. For the finned tubes, the fin efficiency at the condensing region was calculated with a semi-empirical correlation obtained in the previous basic study. The effect of condensate film on the tubes was considered to be negligibly small for the heat transfer and pressure loss calculation. The experimental results for the temperature distributions of water and flue gas in the test heat exchangers with bare and finned tubes agreed well with the prediction.

scholarly journals High Performance Heat Exchanger for Latent Heat Recovery from Flue Gas

2013 ◽  
Vol 79 (803) ◽  
pp. 1363-1374 ◽  
Author(s):  
Junpei YAMASHITA ◽  
Yoshio UTAKA ◽  
Masakazu KOBAYASHI ◽  
Yasuhiro SANO
Keyword(s):  
Heat Exchanger ◽  
Latent Heat ◽  
Flue Gas ◽  
Heat Recovery ◽  
High Performance

Latent heat recovery from actual flue gas

2002 ◽  
Author(s):  
Masahiro Osakabe ◽  
Sachiyo Horiki ◽  
Tsugue Itoh ◽  
Ikuya Haze
Keyword(s):  
Latent Heat ◽  
Flue Gas ◽  
Heat Recovery ◽  
Actual Flue Gas

scholarly journals Effect of Twisted Fin Array in a Triple-Tube Latent Heat Storage System during the Charging Mode

2021 ◽  
Vol 13 (5) ◽  
pp. 2685
Author(s):  
Mohammad Ghalambaz ◽  
Jasim M. Mahdi ◽  
Amirhossein Shafaghat ◽  
Amir Hossein Eisapour ◽  
Obai Younis ◽  
...  
Keyword(s):  
Energy Storage ◽  
Heat Exchanger ◽  
Latent Heat ◽  
Thermal Energy ◽  
Heat Storage ◽  
Hot Water ◽  
Melting Time ◽  
Latent Heat Storage ◽  
Tube Heat Exchanger ◽  
Storage Rate

This study aims to assess the effect of adding twisted fins in a triple-tube heat exchanger used for latent heat storage compared with using straight fins and no fins. In the proposed heat exchanger, phase change material (PCM) is placed between the middle annulus while hot water is passed in the inner tube and outer annulus in a counter-current direction, as a superior method to melt the PCM and store the thermal energy. The behavior of the system was assessed regarding the liquid fraction and temperature distributions as well as charging time and energy storage rate. The results indicate the advantages of adding twisted fins compared with those of using straight fins. The effect of several twisted fins was also studied to discover its effectiveness on the melting rate. The results demonstrate that deployment of four twisted fins reduced the melting time by 18% compared with using the same number of straight fins, and 25% compared with the no-fins case considering a similar PCM mass. Moreover, the melting time for the case of using four straight fins was 8.3% lower than that compared with the no-fins case. By raising the fins’ number from two to four and six, the heat storage rate rose 14.2% and 25.4%, respectively. This study presents the effects of novel configurations of fins in PCM-based thermal energy storage to deliver innovative products toward commercialization, which can be manufactured with additive manufacturing.

Quasi-stationary modelling of solidification in a latent heat storage comprising a plain tube heat exchanger

2018 ◽  
Vol 20 ◽  
pp. 551-559 ◽  
Author(s):  
A. Stamatiou ◽  
S. Maranda ◽  
F. Eckl ◽  
P. Schuetz ◽  
L. Fischer ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Latent Heat ◽  
Heat Storage ◽  
Latent Heat Storage ◽  
Tube Heat Exchanger ◽  
Plain Tube

Prediction and Performance of Compact Latent Heat Recovery Heat Exchanger With Small Diameter Tubes

2007 ◽  
Author(s):  
Masahiro Osakabe
Keyword(s):  
Heat Exchanger ◽  
Power System ◽  
Latent Heat ◽  
Heat Recovery ◽  
Small Diameter ◽  
Cooling Water ◽  
Prediction Method ◽  
Outer Diameter ◽  
Exhaust Gas ◽  
And Performance

The most part of energy losses in power system such as fuel cells is due to the heat released by the exhaust gas to atmosphere. The exhaust gas consists of non-condensable gas and steam with sensible and latent heat. As a lot of latent heat is included in the exhaust gas, its recovery is very important to improve the power system efficiency. Based on the previous basic studies, a thermal hydraulic prediction method for latent heat recovery exchangers was proposed. For the condensation of steam on heat transfer tubes, the modified Sherwood number taking account of the mass absorption effect on the wall was used. Two kinds of compact heat exchanger with staggered banks of bare tubes of 10.5 or 4mm in outer diameter was designed with the prediction method. The more compactness was obtained with the smaller tubes at a designed heat recovery. The thermal hydraulic behavior in the compact heat exchangers was experimentally studied with air-steam mixture gas. In the parametric experiments varying the steam mass concentration, the temperature distributions of cooling water and mixture gas were measured. The experimental results agreed well with the prediction proposed in this study and the more compactness with the smaller tubes was proved.

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