Waste Heat Recovery From the Exhaust of a Diesel Generator Using Shell and Tube Heat Exchanger

2013 ◽  
Author(s):  
Shekh N. Hossain ◽  
Saiful Bari
Keyword(s):  
Computer Simulation ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Heat Recovery ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Diesel Generator ◽  
Tube Heat Exchanger ◽  
Hfc 134A ◽  
Shell And Tube

The heat from exhaust gas of diesel engines can be an important heat source to provide additional power and improve overall engine efficiency. Bottoming Rankine Cycle (RC) is one of the promising techniques to recover heat from the exhaust. One derivative of RC known as Organic Rankine Cycle (ORC) is also suitable for heat recovery for moderate and small size engines as the exhaust heat content and temperature of these engines are low. To recover heat from the exhaust of the engine, an efficient heat exchanger is necessary. In this current research, a shell and tube heat exchanger is optimized by computer simulation for two working fluids, water and HFC-134a. Two shell and tube heat exchangers were purchased and installed into a 40 kW diesel generator. The performance of the heat exchangers using water as the working fluid was then conducted. With the available data, computer simulation was carried out using CFD software ANSYS CFX14.0 to improve the design of the heat exchanger for both fluids. Geometric variables including length, number of tubes, and baffle design are all tested separately. Using the optimized heat exchangers simulation was conducted to estimate the possible additional power generation considering 80% isentropic turbine efficiency. The proposed heat exchanger was able to produce 11% and 9.4 % additional power using water and HFC-134a as the working fluid at maximum working pressure of 15 and 40 bar respectively. This additional power results into 12% and 11% improvement in brake-specific fuel consumption (bsfc) by using water and HFC-134a respectively. This indicates that besides water, organic fluids can also be a suitable option to recover heat from the exhaust of diesel engine.

Effect of Heat Exchanger Orientations to Recover Heat From the Exhaust of a Diesel Generator Using Rankine Cycle (RC)

2015 ◽  
Author(s):  
S. Bari ◽  
Shekh N. Hossain
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Diesel Generator ◽  
Working Pressure ◽  
Exhaust Heat ◽  
Parallel Arrangement ◽  
Shell And Tube ◽  
Geometric Variables

The heat from the exhaust gas of diesel engines can be an important heat source to provide additional power and improve overall engine efficiency. Studies related to the applications of recoverable heat to produce additional power using separate Rankine cycle are scare. To recover heat from the exhaust of an engine, an efficient heat exchanger is necessary. For this type of application, the heat exchangers are needed to be designed in such a way that it can handle the heat load with reasonable size, weight and pressure drop. In this project, experiments were conducted to measure the exhaust heat available from a 40 kW diesel generator at different loads. Shell and tube heat exchangers were purchased and installed into the engine. The performance of the heat exchangers using water as the working fluid was then conducted. With the available data, computer simulation was carried out using CFD software CFX to improve the design of the heat exchangers. Geometric variables including length, number and diameter of tubes, and baffle design were all tested separately. Upon investigating how these parameters influenced the heat exchangers’ effectiveness, optimum design of shell and tube heat exchangers was proposed. The proposed heat exchangers were manufactured and experiment was conducted. Two heat exchangers were used to generate superheated steam. These two heat exchangers were arranged in two orientations namely, series and parallel. The proposed heat exchanger was able to produce 2.71 kW additional power using water as the working fluid at an optimum working pressure of 15 bar using parallel arrangement. It was found that parallel arrangement generated 10% more additional power than the series arrangement.

scholarly journals Study on Shell-and-Tube Heat Exchanger Models with Different Degree of Complexity for Process Simulation and Control Design

2018 ◽  
Author(s):  
Javier Bonilla
Keyword(s):  
Heat Exchanger ◽  
Molten Salt ◽  
Heat Exchangers ◽  
Control Strategies ◽  
Thermal Storage ◽  
Working Fluid ◽  
Tube Heat Exchanger ◽  
Test Loop ◽  
Shell And Tube ◽  
Thermal Oil

Many commercial solar thermal power plants rely on indirect thermal storage systems in order to provide a stable and reliable power supply, where the working fluid is commonly thermal oil and the storage fluid is molten salt. The thermal oil - molten salt heat exchanger control strategies, to charge and discharge the thermal storage system, strongly affect the performance of the whole plant. Shell-and-tube heat exchangers are the most common type of heat exchangers used in these facilities. With the aim of developing advanced control strategies accurate and fast dynamic models of shell-and-tube heat exchangers are essential. For this reason, several shell-and-tube heat exchanger models with different degrees of complexity have been studied, analyzed and validated against experimental data from the CIEMAT-PSA molten salt test loop for thermal energy systems facility. Simulation results are compared in steady-state as well as transient predictions in order to determine the required complexity of the model to yield accurate results.

scholarly journals Modelling of Polymeric Shell and Tube Heat Exchangers for Low-Medium Temperature Geothermal Applications

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2737
Author(s):  
Francesca Ceglia ◽  
Adriano Macaluso ◽  
Elisa Marrasso ◽  
Maurizio Sasso ◽  
Laura Vanoli
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Power Plants ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Heat Transfer Area ◽  
Geothermal Fluid ◽  
Shell And Tube

Improvements in using geothermal sources can be attained through the installation of power plants taking advantage of low and medium enthalpy available in poorly exploited geothermal sites. Geothermal fluids at medium and low temperature could be considered to feed binary cycle power plants using organic fluids for electricity “production” or in cogeneration configuration. The improvement in the use of geothermal aquifers at low-medium enthalpy in small deep sites favours the reduction of drilling well costs, and in addition, it allows the exploitation of local resources in the energy districts. The heat exchanger evaporator enables the thermal heat exchange between the working fluid (which is commonly an organic fluid for an Organic Rankine Cycle) and the geothermal fluid (supplied by the aquifer). Thus, it has to be realised taking into account the thermodynamic proprieties and chemical composition of the geothermal field. The geothermal fluid is typically very aggressive, and it leads to the corrosion of steel traditionally used in the heat exchangers. This paper analyses the possibility of using plastic material in the constructions of the evaporator installed in an Organic Rankine Cycle plant in order to overcome the problems of corrosion and the increase of heat exchanger thermal resistance due to the fouling effect. A comparison among heat exchangers made of commonly used materials, such as carbon, steel, and titanium, with alternative polymeric materials has been carried out. This analysis has been built in a mathematical approach using the correlation referred to in the literature about heat transfer in single-phase and two-phase fluids in a tube and/or in the shell side. The outcomes provide the heat transfer area for the shell and tube heat exchanger with a fixed thermal power size. The results have demonstrated that the plastic evaporator shows an increase of 47.0% of the heat transfer area but an economic installation cost saving of 48.0% over the titanium evaporator.

Additional Power Generation From Waste Energy of Diesel Engine Using Parallel Flow Shell and Tube Heat Exchanger

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Shekh N. Hossain ◽  
S. Bari
Keyword(s):  
Power Generation ◽  
Heat Exchanger ◽  
Diesel Engine ◽  
Heat Exchangers ◽  
Parallel Flow ◽  
Working Fluid ◽  
Exhaust Gas ◽  
Working Pressure ◽  
Tube Heat Exchanger ◽  
Shell And Tube

High temperature diesel engine exhaust gas can be an important source of heat to operate a bottoming Rankine cycle to produce additional power. In this research, an experiment was performed to calculate the available energy in the exhaust gas of an automotive diesel engine. A shell and tube heat exchanger was used to extract heat from the exhaust gas, and the performance of two shell and tube heat exchangers was investigated with parallel flow arrangement using water as the working fluid. The heat exchangers were purchased from the market. As the design of these heat exchangers was not optimal, the effectiveness was found to be 0.52, which is much lower than the ideal one for this type of application. Therefore, with the available experimental data, the important geometric aspects of the heat exchanger, such as the number and diameter of the tubes and the length and diameter of the shell, were optimized using computational fluid dynamics (CFD) simulation. The optimized heat exchanger effectiveness was found to be 0.74. Using the optimized heat exchangers, simulation was conducted to estimate the possible additional power generation considering 70% isentropic turbine efficiency. The proposed optimized heat exchanger was able to generate 20.6% additional power, which resulted in improvement of overall efficiency from 30% to 39%. Upon investigation of the effect of the working pressure on additional power generation, it was found that higher additional power can be achieved at higher working pressure. For this particular application, 30 bar was found to be the optimum working pressure at rated load. The working pressure was also optimized at part load and found that 2 and 20 were the optimized working pressures for 25% and 83% load. As a result 1.8% and 13.3% additional power were developed, respectively. Thus, waste heat recovery technology has a great potential for saving energy, improving overall engine efficiency, and reducing toxic emission per kilowatt of power generation.

scholarly journals Experimental Investigation and Comparison of Shell Tube and Plate Heat Exchanger used in Water Chillers

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Shamkuwar S.C ◽  
◽  
Nitin Chopra ◽  
Mihir Kulkarni ◽  
Nikhil Ahire ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Plate Heat Exchanger ◽  
Working Fluid ◽  
Plate Heat ◽  
Tube Heat Exchanger ◽  
Overall Heat Transfer Coefficient ◽  
Shell And Tube

The main objective of the paper is to compare the performance of Shell and tube heat exchanger (STHE) and Plate heat exchanger (PHE) used in chillers. The paper deals with experimental investigation and comparison, which is based on actual testing of STHE and PHE. Both heat exchangers were designed and tested for a heat load of 6000 kcal/hr. In both types of heat exchangers, the primary working fluid used is Refrigerant R22 and secondary working fluid used is water. Theoretical analysis shows that PHE has a 9.67 % less heat transfer area than STHE. Experimental results show that overall heat transfer coefficient (OHTC) for PHE is higher than STHE by 30.96%. The paper also includes a comparison of the heat transfer rate (Q) of the two heat exchangers experimentally.

Economic Optimization of Shell and Tube Heat Exchanger Based on Constructal Theory

2010 ◽  
Author(s):  
Majid Amidpour ◽  
Abazar Vahdat Azad
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Constructal Theory ◽  
Economic Optimization ◽  
Total Cost ◽  
Tube Heat Exchanger ◽  
Capital Costs ◽  
Operational Energy ◽  
Shell And Tube

In this paper, the new approach of Constructal theory has been employed to design shell and tube heat exchangers. Constructal theory is a new method for optimal design in engineering applications. The purpose of this paper is optimization of shell and tube heat exchangers by reduction of total cost of the exchanger using the constructal theory. The total cost of the heat exchanger is the sum of operational costs and capital costs. The overall heat transfer coefficient of the shell and tube heat exchanger is increased by the use of constructal theory. Therefore, the capital cost required for making the heat transfer surface is reduced. Moreover, the operational energy costs involving pumping in order to overcome frictional pressure loss are minimized in this method. Genetic algorithm is used to optimize the objective function which is a mathematical model for the cost of the shell and tube heat exchanger and is based on constructal theory. The results of this research represent more than 50% reduction in costs of the heat exchanger.

Deflections of A Multipass Shell-and-Tube Heat Exchanger Bolted Joint Subjected to Nonaxisymmetric Thermal Loading

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Natalia Petrova ◽  
Abdel-Hakim Bouzid
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Thermal Loading ◽  
Cocurrent Flow ◽  
Finite Element Models ◽  
Bolted Joint ◽  
Tube Heat Exchanger ◽  
Specific Geometry ◽  
Shell And Tube

Despite the fact that multipass shell-and-tube heat exchangers operating at high temperature are subject to frequent problems related to flange sealing, there is neither detailed explanations for the reasons of the failures nor an adequate solution to this problem. Specific geometry of multipass heat exchangers and the temperature difference between the inlet and the outlet fluids is responsible for the existence of a thermal circumferential gradient at the shell-to-channel bolted joint. However, existing flange design methods do not address nonaxisymmetrical temperature loading of the flanged joint assembly. The circumferential thermal gradient, as the cause of frequent failures to seal the flanged joints, is ignored. This paper outlines the analytical modeling of a flanged joint with a tube sheet of a multipass heat exchanger subjected to a nonaxisymmetrical thermal loading. A shell-and-tube heat exchanger of 51 in. diameter with cocurrent flow was used for analysis. The main steps of the theoretical analysis used for the determination of the circumferential temperature profiles and the thermal expansion displacements and distortions of the bolted joint components are given. The results from the proposed analytical model are compared with those obtained from finite element models.

A Numerical Algorithm and a Graphical Method to Size a Heat Exchanger

2011 ◽  
Author(s):  
Torsten Berning
Keyword(s):  
Heat Exchanger ◽  
Numerical Algorithm ◽  
Heat Exchangers ◽  
Graphical Method ◽  
Application Software ◽  
Microsoft Excel ◽  
Tube Heat Exchanger ◽  
Overall Heat Transfer Coefficient ◽  
Heat Exchanger Design ◽  
Shell And Tube

This paper describes the development of a numerical algorithm and a graphical method that can be employed in order to determine the overall heat transfer coefficient inside heat exchangers. The method is based on an energy balance and utilizes the spreadsheet application software Microsoft Excel™. The application is demonstrated in an example for designing a single pass shell and tube heat exchanger that was developed in the Department of Materials Technology of the Norwegian University of Science and Technology (NTNU) where water vapor is superheated by a secondary oil cycle. This approach can be used to reduce the number of hardware iterations in heat exchanger design.

scholarly journals Performance assessment of shell and tube heat exchanger based subcritical and supercritical organic Rankine cycles

2018 ◽  
Vol 22 (Suppl. 3) ◽  
pp. 855-866
Author(s):  
Anil Erdogan ◽  
Ozgur Colpan
Keyword(s):  
Heat Exchanger ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
System Level ◽  
Two Phase ◽  
Detailed Model ◽  
Tube Heat Exchanger ◽  
Organic Rankine Cycles ◽  
Level Model ◽  
Shell And Tube

In this study, thermal models for subcritical and supercritical geothermal powered organic Rankine cycles are developed to compare the performance of these cycle configurations. Both of these models consist of a detailed model for the shell and tube heat exchanger integrating the geothermal and organic Rankine cycles sides and basic thermodynamic models for the rest of the components of the cycle. In the modeling of the heat exchanger, this component was divided into sever?al zones and the outlet conditions of each zone were found applying logarithmic mean temperature difference method. Different Nusselt correlations according to the relevant phase (single, two-phase, and supercritical) were also included in this model. Using the system-level model, the effect of the source temperature on the performances of the heat exchanger and the organic Rankine cycle was assessed. These performance parameters are heat transfer surface area and pressure drop of tube side fluid for the heat exchanger, and electrical and exergetic efficiencies of the integrated organic Rankine cycles system. It was found that 44.12% more net power is generated when the supercritical organic Rankine cycle is used compared to subcritical organic Rankine cycle.

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