scholarly journals Energy Recovery from an Industrial Clothes Dryer Using a Condensing Heat Exchanger

2021 ◽  
Author(s):  
Yousuf Farooq
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heat Exchanger ◽  
Heat Recovery ◽  
Cold Water ◽  
Waste Heat ◽  
Interface Temperature ◽  
Sensible Heat ◽  
Clothes Dryer ◽  
Condensing Heat Exchanger

The aim of this project was to design a condensing heat exchanger to recover waste heat from an industrial clothes dryer. Industrial cloth dryers are inefficient in their use of energy because almost all of the energy input in the dryer is wasted in the atmosphere, and thus there is great potential for heat recovery. This energy can be used to preheat the incoming cold water, and the conventional heater can then heat the water to a final temperature. The warm moist air from the dryer carries both sensible and latent heat, and in order to design this heat recovery condensing heat exchanger, the heat transfer by both mass and sensible heat has to be accounted for. The basis of this heat and mass transfer problem was the energy balance at the interface, and separate models for the calculation of latent and sensible heat transfer were used. The mass transfer coefficients were obtained from an analogy with heat transfer, and the unknown interface temperature was solved for iteratively. The data for this design was collected from a 20 kW dryer, and the heat recovery from that dryer was observed to be about 17.3%. This heat recovery condensing heat exchanger efficiency can be enhanced by the addition of more coils to the heat exchanger. An improvement in the overall results can be expected if a practical study is done on the condensation heat exchanger for an industrial cloth dryer.

scholarly journals Energy Recovery from an Industrial Clothes Dryer Using a Condensing Heat Exchanger

2021 ◽  
Author(s):  
Yousuf Farooq
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heat Exchanger ◽  
Heat Recovery ◽  
Cold Water ◽  
Waste Heat ◽  
Interface Temperature ◽  
Sensible Heat ◽  
Clothes Dryer ◽  
Condensing Heat Exchanger

The aim of this project was to design a condensing heat exchanger to recover waste heat from an industrial clothes dryer. Industrial cloth dryers are inefficient in their use of energy because almost all of the energy input in the dryer is wasted in the atmosphere, and thus there is great potential for heat recovery. This energy can be used to preheat the incoming cold water, and the conventional heater can then heat the water to a final temperature. The warm moist air from the dryer carries both sensible and latent heat, and in order to design this heat recovery condensing heat exchanger, the heat transfer by both mass and sensible heat has to be accounted for. The basis of this heat and mass transfer problem was the energy balance at the interface, and separate models for the calculation of latent and sensible heat transfer were used. The mass transfer coefficients were obtained from an analogy with heat transfer, and the unknown interface temperature was solved for iteratively. The data for this design was collected from a 20 kW dryer, and the heat recovery from that dryer was observed to be about 17.3%. This heat recovery condensing heat exchanger efficiency can be enhanced by the addition of more coils to the heat exchanger. An improvement in the overall results can be expected if a practical study is done on the condensation heat exchanger for an industrial cloth dryer.

Methods of Thermal Calculations for a Condensing Waste-Heat Exchanger

2014 ◽  
Vol 35 (4) ◽  
pp. 447-461 ◽  
Author(s):  
Paweł Rączka ◽  
Kazimierz Wójs
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Water Vapour ◽  
Flue Gas ◽  
Waste Heat ◽  
Pilot Scale ◽  
Dew Point ◽  
Steam Boiler ◽  
Heat Transfer Area ◽  
Condensing Heat Exchanger

Abstract The paper presents the algorithms for a flue gas/water waste-heat exchanger with and without condensation of water vapour contained in flue gas with experimental validation of theoretical results. The algorithms were used for calculations of the area of a heat exchanger using waste heat from a pulverised brown coal fired steam boiler operating in a power unit with a capacity of 900 MWe. In calculation of the condensing part, the calculation results obtained with two algorithms were compared (Colburn-Hobler and VDI algorithms). The VDI algorithm allowed to take into account the condensation of water vapour for flue gas temperatures above the temperature of the water dew point. Thanks to this, it was possible to calculate more accurately the required heat transfer area, which resulted in its reduction by 19 %. In addition, the influence of the mass transfer on the heat transfer area was taken into account, which contributed to a further reduction in the calculated size of the heat exchanger - in total by 28% as compared with the Colburn-Hobler algorithm. The presented VDI algorithm was used to design a 312 kW pilot-scale condensing heat exchanger installed in PGE Belchatow power plant. Obtained experimental results are in a good agreement with calculated values.

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.

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 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. 

Optimum waste heat recovery from diesel engines: Thermo-economic assessment of nanofluid-based systems using a robust evolutionary approach

2017 ◽  
Vol 233 (1) ◽  
pp. 65-82
Author(s):  
Moslem Yousefi ◽  
Danial Hooshyar ◽  
Joong H Kim ◽  
Marc A Rosen ◽  
Heuiseok Lim
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Diesel Engine ◽  
Heat Recovery ◽  
Volume Fraction ◽  
Waste Heat ◽  
Exhaust Heat ◽  
Recovery System ◽  
Heat Recovery System ◽  
Exhaust Heat Recovery

Nearly 30% of the input energy to a diesel engine is wasted through the exhaust gas; thus, considerable attention has been directed toward developing efficient heat recovery systems for these engines. Given the demonstrated ability of nanofluids to boost the heat transfer rate of heat exchangers, these heat transfer fluids merit consideration for use in diesel exhaust heat recovery systems. In this study, the effects of employing nanofluids on the optimum design of these systems are investigated. An existing heat diesel engine exhaust heat recovery system is modeled to work with Al2O3/water and a modified imperialist competitive algorithm is employed for the optimization. Seven variables consisting of five heat exchanger geometric characteristics together with nanoparticle volume fraction and coolant mass flow rate are considered as design variables. The heat exchanger cost and charging rate of the storage tank are optimization objectives, while the greenhouse gas savings of the heat recovery system are assessed for measuring the environmental impact of the energy recovery. The results indicate that the proposed approach can overcome the challenge of finding the near-optimal design of this complex system and using nanofluids enhances the performance of the heat recovery heat exchanger.

Sign in / Sign up

Export Citation Format

Share Document