Waste Heat Recovery Using Matrix Heat Exchanger from the Exhaust of an Automobile Engine for Heating Car’s Passenger Cabin

2014 ◽  
Vol 984-985 ◽  
pp. 1132-1137
Author(s):  
P. Muthusamy ◽  
Palanisamy Senthil Kumar

The main objective of our work is to analysis the heat transfer rate for various fluids with different matrix heat exchanger (MHE) models and flow characteristic in matrix heat exchanger by using computational fluid dynamics (CFD) package with small car. The amount of heat carried by the cold fluid from hot fluid is mainly depends upon the mass flow rate of the working fluid. The heat transfer area per unit volume of tube is more. So, it increases the temperature of the cold fluid. Here, the hot and cold fluids are moving in the alternate tubes of heat exchanger in the counter flow direction. The small amounts of pressure drop are occurred but which is less compared to existing model. Flow disturbances are rectified in the MHE through the modifications made. Since, silicon carbide material is used as a polishing material to avoid the deposit of carbon at the inner side of the flow passage and this waste heat energy is used for heating passenger cabin during winter season. The wood is used as an insulating material to avoid the heat flow from fluid to atmosphere. Keywords-Heat transfer rate, Matrix heat exchanger, Working fluid, Polishing material.

2012 ◽  
Vol 9 (1) ◽  
pp. 85-91
Author(s):  
Mohammad Azim Aijaz ◽  
T. S. Ravikumar

the hot fluid outlet temperature, cold fluid outlet temperature, heat transfer rate and effectiveness at varying hot and cold fluid inlet temperatures using, log mean temperature difference (LMTD) and effectiveness-number of transfer units (ε-NTU) method. The obtained result illustrates how heat transfer rate and effectiveness increases or decreases at varying hot and cold fluid inlet temperatures. The result obtained from both LMTD and å-NTU method gives statistically significant values. The objective of this paper is to find out the optimal temperature at which heat transfer rate and effectiveness are maximum.


SINERGI ◽  
2020 ◽  
Vol 25 (1) ◽  
pp. 51
Author(s):  
Sudiono Sudiono ◽  
Rita Sundari ◽  
Rini Anggraini

This preliminary investigation studied the effect of circular turbulator vortex generator on heat transfer rate and pressure drop in a circular channel countercurrent double pipe heat exchanger with water working fluid. Increasing the number of circular turbulator yielded increasing heat transfer rate and pressure drop. The problem generated when increased pressure drop occurred in relation to more energy consumption of the water pumping system. Therefore, optimization in circular turbulator number is necessary to minimize the pressure drop about distance length between circular turbulator, tube diameter and thickness, type of material and crystal lattice, as well as the geometrical shape of fluid passage (circular or square). This study applied PVC outer tube and copper alloy inner tube, as well as fiberglass circular turbulator. The optimum results showed that seven parts of circular turbulator increasing heat transfer rate by 30% and pressure drop by 80% compared to that passage in the absence of circular turbulator at cool water debit of 7 L/min.


2020 ◽  
Vol 9 (1) ◽  
pp. 1793-1798

A heat exchanger is a device intensively used for enhancing the transfer of heat energy between two or more working fluids at different temperature, which are in thermal contact. The optimal design and efficient operation of heat exchanger and heat transfer network are of a great significance in any of the process industry. The heat transfer efficiency depends on both design of heat exchanger and property of working fluid. From various types of heat exchanger, the double stacked shell and tube heat exchanger with straight tube and single pass is to be under study. Here the redesign of heat exchanger takes place with the key objectives of optimizing the pressure drop, optimizing the heat transfer rate and reducing the saddle support weight used for cooling purpose in brewery application. The design calculations are carried out using the Kerns and Bell Delwar method and other important parameters dealing with material selection and geometries are also taken into consideration. FEA analysis for optimizing the saddle support weight is carried out using Dassault systeme’s Solidworks while the CFD analysis for optimizing pressure drop and heat transfer rate is carried out using Dassault systeme’s Solidworks analysis software and the design and working of Shell and tube heat exchanger is determined in terms of variables such as pressure ,temperature ,mass flow rate ,flow rate ,energy input output that are of particular interest in Shell and tube heat exchanger analysis.


2016 ◽  
Vol 831 ◽  
pp. 223-231 ◽  
Author(s):  
Robert Smusz ◽  
Joanna Wilk

The paper presents the preliminary design of the special heat exchanger. The device under consideration is the kind of immersed coil heat exchangers. It consists of three vertical coils: two coils are standard, water is used as a heating medium; one coil is filled by the refrigerant R134a which transfers the waste heat from refrigeration and air conditioning system during the boiling processes. In order to prevent the possible refrigerant leakage, the special buffer layer filled with the nanofluid is mounted in the Freon coil. Thermophysical properties of the nanofluid cause the intensification of the heat transfer through the buffer layer and the same increase of the heat transfer rate. Calculations of thermal power were made. Correlations of heat transfer coefficients in curved tubes, pressure drop correlations for flow through helical coil tubes and correlations describing the heat transfer in the buffer layer, were applied. Results of the calculations indicate of the influence of of Freon coil on the exchanger heat transfer rate. Heat power of Freon coil is about 7 – 25% of water coil thermal power. Thus, the waste heat applied significantly increases the exchanger heat transfer rate.


2014 ◽  
Vol 22 (04) ◽  
pp. 1450026 ◽  
Author(s):  
HONGGI CHO ◽  
TAEHUN KIM ◽  
JUNGHO KIM ◽  
CHANGSEON LEE ◽  
JAEYOUNG CHOI

The present study is aimed to investigate the effect of fin geometry on the performance of a concentric heat exchanger with the commercial CFD software of Star CCM+. In general, the concentric heat exchanger consists of inner and outer tubes. The inner tube has a lot of serrated fins spirally manufactured on its surface in order to increase the heat transfer performance. A simplified simulation model has been applied to simulate the performance of the concentric heat exchanger in this study. Both inner and outer tubes have the same length of 60 mm. The inner diameter of outer tube is 17.05 mm. The outer diameter of inner tube before manufacturing fins is 11.5 mm. Water is used as a working fluid and the concentric heat exchanger has a counter-flow configuration. The simulation parameters were fin height, fin thickness and fin width. It was found that heat transfer rate increased by 3–4% as the fin height increased from 0.95 to 1.15 mm. However, pressure drop increased highly by 39–41%. The effectiveness, which could be evaluated by calculating the ratio of enhancement of heat transfer rate to that of pressure drop, was about 74% for the fin height of 1.15 mm. In case of fin height of 1.05 mm, the effectiveness was 88% due to the increase in pressure drop, about 15%, compared with the base fin height of 0.95 mm. Also, it was noted that the effectiveness was about 88% and 95% for the fin thickness of 0.5 and 0.4 mm, respectively, compared with the base fin thickness of 0.3 mm. In case of increasing the fin width from 0.8 to 1.2 mm, the heat transfer rates slightly increased by 1–2% and the pressures drops increased by 3–4%. Hence, the effectiveness was about 98% for the fin width of 1.2 mm. And the effectiveness for the fin width of 1.0 mm was 97%. Based on the simulation results, it was concluded that maximum heat transfer rate has been obtained when the fin height is 1.15 mm. However, pressure drop is considerably increased by 39–41%. Therefore, the fin height should be carefully determined according to the criteria of pressure drop.


CFD letters ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 37-60
Author(s):  
Mohammadreza Hasandust Rostami ◽  
Barat Ghobadian ◽  
Gholamhassan Najafi ◽  
Ali Motevali ◽  
Nor Azwadi Che Sidik

In this research, the thermal attributes of shell and finned tube heat exchanger such as thermal efficiency, pressure drop, heat transfer rate and average temperature in the tube side of heat exchanger with using the different volume concentration of nanoparticles (SWCNT and Graphene quantum dot) at the various Reynolds number by applying either fin blades and without fin blades have been conducted numerically. In this heat exchanger the hot fluid or nanofluid flows in the tube section and cold fluid or pure water moves in the shell side. As regarding to results obtained the majority of thermal characteristics like heat transfer rate, pressure drop and effectiveness enhanced with augmentation of Reynolds number and increasing of volume concentration of nanofluids to 1% volumetric of working fluid whereas at the higher volume concentrations of nanoparticles (upper from 1% volumetric) the thermal properties of heat exchanger decreased generally. Also pressure drop intensifies with increment of Reynolds number and volume concentration of nanoparticles that at higher Reynolds number the effects of nanoparticles on the pressure drop were more noticeable. The average temperature of heat exchanger in the end section of inside tubes increased with augmentation of Reynolds number and nanoparticles. Finally, according to the results obtained in this study, most impression on the thermal attributes enhancement was found by employing of finned tubes compared to other factor which this factor increased heat transfer rate of heat exchanger by almost 188% also the effects of nanoparticles at the high levels of volume concentration especially for 5% of SWCNT nanoparticle on the pressure drop obtained about 80% compared to the base fluid.


2021 ◽  
pp. 195-195
Author(s):  
Muhammad Khan ◽  
Yong Song ◽  
Qunying Huang

Due to compact size, high power density, low cost and short construction time, the Small Modular Reactors (SMRs) are considered as one of the candidate reactors, in which the power generation system is important with a compact heat exchanger for modular construction. Therefore, the effect of plate structure and nature of the working fluid on the thermal performance of Plate Heat Exchanger (PHE) are analyzed for the design of compact and efficient heat exchanger. The heat transfer rate, temperature counters, velocity vectors and pressure drop have been optimized and investigated using FLUENT. The Nusselt number has been calculated for the corrugated and flat PHE to validate the convective heat transfer. The numerical results are agreed well with correlation within deviation of ~ 5-7%. The performance of heat exchanger can be improved by controlling the mass flow rate and temperature of working fluid. The corrugation PHE increases the heat transfer rate 20 % and effectiveness 23 %, respectively, as compare to flat PHE when the working fluid is water. In the case of air, heat transfer rate and effectiveness are about 10 % and 9 %, respectively. The results show that the corrugated PHE is more effective than the flat PHE because corrugation pattern enhances the turbulence of fluids, which further increase heat transfer rate and coefficient. The selection of the working fluid and structure of the plate must be considered carefully for efficient and compact design of heat exchanger.


Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6761
Author(s):  
Junhyeok Yong ◽  
Junggyun Ham ◽  
Ohkyung Kwon ◽  
Honghyun Cho

In this study, the heat exchange characteristics of water–LiBr solutions used as working fluid in a plate heat exchanger (PHE) were experimentally investigated at various concentrations. To analyze the heat transfer characteristics under LiBr/water conditions, a brazing type plate heat exchanger was installed, and the LiBr concentration on the high-temperature side was controlled at 56%, 58%, 60% and 60%. The results showed that the average heat transfer rate under water/water conditions was higher than that under LiBr/water conditions and the average heat transfer rate decreased as the LiBr concentration on the hot side increased. In addition, under both water/water and LiBr/water conditions, the average heat transfer rate and overall heat transfer coefficient increased as the mass flow rate of the working fluid on the hot side increased. When LiBr was used, the Reynolds number (Re) of LiBr on the hot side was more than nine times lower than that of water at the same mass flow rate owing to the influence of the increased viscosity. Based on the data obtained from the water/water and LiBr/water experiments, a correlation for predicting the Nusselt number (Nu) on the hot side in a wide range was developed.


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