Heat Transfer and Pressure Drop Investigations of the Compact Exhaust Heat Exchanger With Twisted Tape Inserts for Automotive Waste Heat Utilization

2020 ◽  
Vol 13 (4) ◽  
Author(s):  
Dhruv Raj Karana ◽  
Rashmi Rekha Sahoo
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Internal Heat ◽  
Decisive Role ◽  
Twisted Tape ◽  
Twisted Tapes ◽  
Exhaust Heat

Abstract Thermoelectric-based waste heat recovery is a competent technique to reduce the exhaust emissions and fuel consumption of automobiles. Thermal and hydraulic characteristics of the exhaust heat exchanger plays a decisive role in the extent of waste heat recovery from the exhaust gas. In this study, the exhaust heat exchanger having twisted tape inserts is proposed to increase the internal heat transfer coefficient. The dimensionless Nusselt number and friction factor were evaluated experimentally for different designs of the twisted tapes. The experiments were performed for the Reynolds number in the range 2300–25000. The considered geometric parameters of the twisted rib explored were the pitch fraction, twist fraction, and slope. The obtained results were compared to reveal the best feasible design of the twisted tape. The maximum net thermohydraulic efficiency factor achieved for the system in the present analysis is 1.93. With the use of twisted tapes, the area of the exhaust heat exchanger can be greatly reduced for the same power output as flat geometry. This would help for the integration of the waste heat recovery with the engine, where the space available is very limited.

The Potential Danger of Fire in Gas Turbine Heat Exchangers

1969 ◽  
Author(s):  
C. F. McDonald
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Heat Exchangers ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Engine Operation ◽  
Exhaust Heat ◽  
The Subject ◽  
Gas Turbine Cycle

Increased emphasis is being placed on the regenerative gas turbine cycle, and the utilization of waste heat recovery systems, for improved thermal efficiency. For such systems there are modes of engine operation, where it is possible for a metal fire to occur in the exhaust heat exchanger. This paper is intended as an introduction to the subject, more from an engineering, than metallurgical standpoint, and includes a description of a series of simple tests to acquire an understanding of the problem for a particular application. Some engine operational procedures, and design features, aimed at minimizing the costly and dangerous occurrence of gas turbine heat exchanger fires, are briefly mentioned.

Exhaust Heat Recovery Unit Equipped With Nanofluid and Helical Tapes, a Solution for Cleaner Energy Production

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
M. Sheikholeslami ◽  
A. Arabkoohsar ◽  
M. Jafaryar
Keyword(s):  
Nusselt Number ◽  
Heat Exchanger ◽  
Environmental Impacts ◽  
Flue Gas ◽  
Heat Recovery ◽  
Internal Combustion Engines ◽  
Waste Heat ◽  
Physical Parameters ◽  
Twisted Tape ◽  
Exhaust Heat

Abstract In internal combustion engines (ICE), a major part of the generated energy via burning the fuel is wasted. The cooling fluid controlling the temperature, the reclaimed hot gases for reducing the environmental impacts, and the hot combustion productions leaving the engine from the exhaust are the main origins of energy waste in such a machine. Waste heat recovery and flue gas condensation are the methods by which the overall efficiency of a thermal engine is enhanced, and its environmental impacts are mitigated. In this paper, the utilization of the exhaust waste energy of ICE by using a heat exchanger with nanofluid and helical tape, in order to augment the thermal performance of the engine and reduce its environmental impact, is investigated numerically. In this heat exchanger, the flue gas of the engine at high temperature and H2O-CuO nanofluid are considered as the primary and secondary working fluids, and the twisted tape makes the flow further disturbed so that a larger overall heat transfer coefficient is obtained. The finite volume method has been applied to scrutinize the impacts of Reynolds number as well as the twisting-tape turns number on the operation and performance of the tube. As such, suitable correlations for the prediction of some of the thermos-physical parameters of the problem (such as Nusselt number and Darcy factor) are extracted regarding the obtained data. The results of the study reveal that Nusselt number is higher for larger numbers of the tape turn and higher Reynolds numbers, while a lower friction factor is achieved as the number of the turns is reduced.

scholarly journals Heat Transfer Characteristics of Calcined Petroleum Coke in Waste Heat Recovery Process

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Bin Zheng ◽  
Yongqi Liu ◽  
Lichen Zou ◽  
Ruiyang Li
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Petroleum Coke ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Recovery Process ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Calcined Petroleum Coke

This paper reports the results of heat transfer characteristics of calcined petroleum coke in waste heat recovery process. The model of heat exchanger was set up. The model has been used to investigate the effects of porosity (0.58 to 0.79), equivalent heat conductivity coefficient (0.9 to 1.1), and equivalent specific heat (0.9 to 1.1). The calculated values of calcined petroleum coke temperature showed good agreement with the corresponding available experimental data. The temperature distribution of calcined petroleum coke, the calcined petroleum coke temperature at heat exchanger outlet, the average heat transfer coefficient, and the heat recovery efficiency were studied. It can also be used in deriving much needed data for heat exchanger designs when employed in industry.

scholarly journals Design and Development of Innovative Protracted-Finned Counter Flow Heat Exchanger (PFCHE) for an Engine WHR and Its Impact on Exhaust Emissions

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2717 ◽  
Author(s):  
Rajesh Ravi ◽  
Senthilkumar Pachamuthu
Keyword(s):  
Heat Exchanger ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Gas Temperature ◽  
Counter Flow ◽  
Exhaust Heat ◽  
Recovery System ◽  
Heat Recovery System ◽  
Flow Heat

This article describes and evaluates an Organic Rankine Cycle (ORC) for waste heat recovery system both theoretically as well as experimentally. Based on the thermodynamic analysis of the exhaust gas temperature identified at different locations of the exhaust manifold of an engine, the double-pipe, internally–externally protruded, finned counter flow heat exchanger was innovatively designed and installed in diesel engine for exhaust waste heat recovery (WHR). The tests were conducted to find the performance of heat recovery system by varying the fin geometries of the heat exchanger. The effect of heat exchanger on emission parameters is investigated and presented in this work. The experimental results demonstrated that the amount of heat transfer rate, the effectiveness of heat exchange rand the brake thermal efficiency improved with an increase in length and number of the fins. A significant reduction was observed in all major emissions after the implementation of catalytic-coated, protracted finned counter flow heat exchanger. It also demonstrated the possibility of electric power production using steam turbo-electric-generator setup driven by the recovered exhaust heat energy.

scholarly journals Parametric study on heat transfer characteristics of waste heat recovery heat exchanger for automotive exhaust thermoelectric generator

2018 ◽  
Vol 7 (3.3) ◽  
pp. 6
Author(s):  
Ki. Hyun Kim ◽  
Mahesh Suresh Patil ◽  
Jae Hyeong Seo ◽  
Chan Jung Kim ◽  
Gee Soo Lee ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Exchanger ◽  
Numerical Analysis ◽  
Pressure Drop ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics

Background/Objectives: The parametric study on heat transfer characteristics of waste heat recovery heat exchanger was carried out by varying different geometry parameters to suggest optimum model for automotive exhaust thermoelectric generator.Methods/Statistical analysis: The numerical analysis method was applied to compare the heat transfer characteristics of various heat exchanger models. For numerical analysis, various models were created using computer aided drawing considering different fin arrangements and guide plates. Commercial code ANSYS 17.0 was used to analyze the heat transfer and fluid flow behavior of various models. Mesh independency was conducted to enhance the accuracy of the results.Findings: The thermal performance analysis of waste heat recovery heat exchanger was conducted considering pressure drop and heat flux at cooling side. As the fin spaces were increased, the heat flux at cooling side increased, but pressure drop also increased.Improvements/Applications: The developed geometry can be further optimized considering other geometry parameters and efficient system could be developed for power generation using waste heat with heat recovery exchanger and the present study provides detailed numerical analysis considering pressure drop and heat flux. 

Performance evaluation of metal-foam baffle exhaust heat exchanger for waste heat recovery

2020 ◽  
Vol 266 ◽  
pp. 114875 ◽  
Author(s):  
Tianyu Chen ◽  
Gequn Shu ◽  
Hua Tian ◽  
Tingting Zhao ◽  
Hongfei Zhang ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Heat Exchanger ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Metal Foam ◽  
Waste Heat ◽  
Exhaust Heat
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