The slightest difference in plumbing can make a flow difference. Heat exchangers are used in engines of cars, ships, and planes to improve the efficiency of the engine and are also used in refrigerators and air conditioners. This experiment was conducted by using parallel and counter flow heat exchanger to study, understand and visualise the heat transfer phenomena in both parallel and counter flow equipment. Entropy generation analysis of parallel and counterflow threefluid heat. Large volumes of vapor may be condensed using this type of heat exchanger flow. The present work is directed towards the modeling of shell and tube parallel flow heat. The materialprocess decision on a parallel flow heat exchanger. Representation of parallel flow heat exchanger heat transfer home category mechanical engineering mcq questions and answers heat transfer previous.
But of the three, the counter flow heat exchanger design is the most efficient when comparing heat transfer rate. However, there are applications where parallel flow has its benefits, such as when limiting the transfer of heat is recommended. Difference in counter and parallel flow heat exchanger. Fundamentals of heat exchanger design download ebook pdf. Heat is transferred from the warm fluid through the wall of the inner tube the socalled heating surface to the cold fluid. Heat exchanger airwater, applied to the current paper, due to the flow of fluids in the same direction is called the heat exchanger with the parallel flow 1. Review of experimental analysis of parallel and counter flow heat. Faculty of chemical engineering laboratory submission form name vengadeesh verasamy 1103151018 title of experiment experiment 5. Experimental analysis of performance of heat exchanger with plate. The term heat exchanger applies to all equipment used to transfer heat between two streams. Double pipe heat exchanger design requires use of the heat transfer rate, the log mean temperature difference, and an estimate of the overall heat transfer coefficient to calculate the estimated heat transfer surface area. Parallel and counter flow heat exchanger course code ekb 2091 course name chemical engineering lab 11 group member id mohamed aadil ashraff 1103151010 criteria very poor poor good very good excellen t 1. Asee 2014 zone i conference, april 35, 2014, university of.
A double pipe heat exchanger consists of one pipe inside another. In general, parallel flow heat exchangers considered less efficient than counter flow heat exchangers in terms of transferring heat from one fluid to another. Click download or read online button to get fundamentals of heat exchanger design book now. Heattransfer characteristics of wet heat exchangers in. Plate heat exchangers were first produced in the 1920s and have since been widely used in a great number of sectors a plate exchanger consists of a series of parallel plates that are placed one above the other so as to allow the formation of a series of channels for fluids to flow between them. Heat exchangers 73 individual thermal resistances of the system. The inlet temperature of cooled fluid has insignificant impact on heat exchanger effectiveness. Difference in counter heat exchanger and parallel flow heat. Parallel flow and counterflow heat exchangers are often compared. There have been reported cases of heat exchanger failure in service due to the. The dimensions and parameters of microchannel with 40 mm. The 3d fulldomain conjugated model based on actual doublelayer microchannel heat exchanger used in experiment in section 3 is adopted, as shown in fig.
If the overall heat transfer coefficient of the heat exchanger is 700 wm 2 c, determine the length of the tube required in order to heat the water to 80 c using a the lmtd method and b the e ntu method. Our main focus is to increase the efficiency of the parallel flow heat exchanger and on the basis of this, decide the shape and size of the heat exchanger. A heat exchanger is a device that is used to transfer thermal energy enthalpy between two or more fluids, between a solid surface and. Investigation of fluid flow and heat transfer characteristics. It is common knowledge amongst heat exchanger designers that a counter flow heat exchanger installation is more efficient than the parallel flow alternative, but for everyone else it can be a bit of a mystery. Temperature profiles in a counter flow and b parallel flow single pass heat exchangers. Ees procedures and functions for heat exchanger calculations. Hot air recirculation tends to reduce the capacity of the heat exchanger, thereby requiring a higher air flow rate andor more heattransfer surface. Heat exchanger has increased immensely from the viewpoint of energy conservation, conversion, recovery, and successful implementation of new energy sources. Previous question next question get more help from chegg. Chapter 5 heat exchangers faculty of engineering and.
Design and development of parallel counter flow heat exchanger. D counter flow heat exchanger is better then the parallel flow because counter flow type is more effective because of the uniform temperature difference between hot and cold fluids throughout the pass compared to parallel flow configuration. Parallel and counter flow designs heat exchangers although ordinary heat exchangers may be extremely different in design and construction and may be of the single or twophase type, their modes of operation and effectiveness are largely determined by the direction of the fluid flow within the exchanger. Representation of parallel flow heat exchanger heat transfer. Heat exchangers with cocurrent flow of the two streams are not very often seen because of the obvious reason that it is possible to do more heat exchange if the two streams are put in countercurrent flow, providing the same heat exchange area, w.
This site is like a library, use search box in the widget to get ebook that you want. July 2016, volume 3, issue 7 jetir issn 2349 5162 numerical. Take a single pass shell and tube exchanger and look at how the temperature changes as we go along the length of it in small segments. Parallel flow to tubes platefin tubefin ordinary separating wall heatpipe wall rotary fixedmatrix rotating. Hot air recirculation tends to reduce the capacity of the heat exchanger, thereby requiring a higher air flow rate andor more heat transfer surface.
In a parallel flow exchanger, both fluids in the heat exchanger flow in the same direction. This hx works in parallel flow, where the water flows by 3ms and the oil is half of the water and the convection is. If water is kept above 32 deg f, freezing can be avoided. This file contains notes on the important topic of ees functions for heat exchanger calculations. The most common arrangements for flow paths within a heat exchanger are counterflow and parallel flow. Counter flow heat exchangers are inherently more efficient than parallel flow heat exchangers because they create a more uniform temperature difference between the fluids, over the entire length of the fluid path. Counter flow heat exchangers can allow the cold fluid to exit with a higher temperature than the exiting hot fluid. Large temperature difference at one end of the heat exchanger causes added thermal stresses and early failure. In this work, heat transfer coefficients of shell and helically coiled tube heat exchanger using al 2 o 3 water nanofluid were studied. C the valve to adjust hot flow rate does not work so we will measurement by ourselves. Heat exchanger shell and tube tutorial cfd cfx statical. The heat exchanger must be isolated from system vibrations using flexible piping connections and isolation pads on the mounting feet. Global control strategy of a parallelflow heat exchanger. Difference in counter heat exchanger and parallel flow.
These notes were prepared while teaching heat transfer course to the m. Why counter flow heat exchangers are more efficient. Dec 26, 2016 parallel flow heat exchanger and counter flow heat exchanger hmt tutorial 20 other subjects from ujjwal kumar sen all sfd and bmd tutorials. Heat exchanger transfer thermal energy from one medium to another. The objective of this experiment is study the heat transfer phenomena in parallel and counter flow arrangements, to calculate the lmtd for both parallel and counter flow. Parallel flow heat exchanger and counter flow heat exchanger. I made a parallelseries heat exchanger for show and tell for the students. Another advantage if parallel flow heat exchangers are used is that outlet temperature of the fluid being cooled can reach a limiting temperature.
R sekulib university of kentucky introduction a heat exchanger is a device that is used for transfer of thermal energy enthalpy between two or more fluids, between a solid surface and a fluid, or between solid particulates and a. A heat exchanger can also be operated in counterflow, in which the two fluids flow in parallel but opposite directions. A counterflow heat exchanger is one in which the direction of the flow of one of the working fluids is opposite to the direction to the flow of the other fluid. Lab 5 parallel and counter flow heat exchanger faculty. A heat exchanger is a device that is used to transfer thermal energy enthalpy between two or more fluids, between a solid surface and a fluid, or between solid particulates and a fluid, at different temperatures and in thermal contact. This hx works in parallel flow, where the water flows by 3ms and the oil is half of the water and the convection is neglected outer the shell.
The simplest heat exchanger is one for which the hot and cold fluids move in the same or opposite directions. Determination of thermal conductivity of insulation powder. The major types of heat exchanger include double pipe, shelltube, plate and shell, plate fin, and phase change heat exchangers. This page was last edited on 23 decemberat is the log mean temperature difference, which is the suitable form of the average temperature difference for use in the analysis of heat exchangers. Other articles where parallelflow heat exchanger is discussed. The two most common heat exchanger design problems are those of rating and sizing. Crossflow, parallel flow, and counterflow heat exchanger configurations are three examples. Double pipe heat exchanger design with counterflow or. Parallel flow heat exchanger and counter flow heat. Note that in a counter flow heat exchanger the outlet temperature of the cold fluid can exceed the outlet temperature of the hot fluid but this cannot happen in a parallel flow system.
Plate heat exchanger phe, where corrugated plates are held in contact and the two fluids flow. Pdf design and development of parallel counter flow heat. While parallel flow arrangement can be beneficial, under certain conditions that reduce the limiting temperature, channeling problems can occur or freeze may be caused at shutdown. The outlet temperature of the cold fluid never exceeds the outlet temperature of. Pdf boundary control of a parallelflow heat exchanger by input. Mar 25, 2020 variation of the fluid temperatures in a parallel flow doublepipe heat exchanger. A heat exchanger is a heat transfer device that exchanges heat between two or more process fluids. It is referred to as a laminar flow heat exchanger if the surface area density is above about 3000 m2m 3 914 ft2ft3, and as a micro heat exchanger if the surface area density is above about 10,000 m2m 3 3050 ft2ft3. A counterflow heat exchanger will require less heat exchange surface area than a parallel flow heat exchanger for the same heat transfer rate and the same inlet and outlet temperatures for the fluids. Pdf in this work, a modified analysis of a parallelflow plate heat exchanger that takes into account a volumetrically uniform. Variation of the fluid temperatures in a parallelflow doublepipe heat exchanger. The effectiveness of a heat exchanger depends on the geometry of the heat exchanger as well as the flow arrangement. Heat transferheat exchangers wikibooks, open books for an.
Temperature difference leads to heat transfer and heat transfer changes the temperature difference. Lets assume we have a perfectly efficient, infinitely long heat exchanger with the same substance on each side, but one enters at 100 f and the other at 0 f. Joseph engineering college, vamanjoor, mangalore, india. What is application of parallel flow heat exchanger. For example, refrigerators use heat exchangers to heat transfer from your groceries to the surrounding air.
Numerical simulations have been performed to investigate the fluid flow and heat transfer characteristics of microchannel heat exchanger. You will need some way to monitor and control flow. Experimental investigation of heat transfer characteristics on a gas. Ppt heat exchanger powerpoint presentation free to.
Experimental study on parallel and counter flow configuration. Parallel is best, but flow will follow the path of least resistance. Aircooled heat exchangers 12631 the intake of the unit or other nearby units. The inlet temperature of cooled fluid has insignificant impact on. Heat exchangers jordan university of science and technology. The design of parallel flow heat exchanger is advantageous when two fluids are required to be. Determination of over all heat transfer coefficient of composite wall. Here, we illustrate the development of the effectiveness relation for the doublepipe parallelflow heat exchanger.
The chemical enters at 20 c at a rate of 3 kgs, while the water enters at 110 c at a rate of 2 kgs. A heat exchanger can have several different flow patterns. Note that in a counterflow heat exchanger the outlet temperature of the cold fluid can exceed the outlet temperature of the hot fluid but this cannot happen in a parallel flow system. Heat exchanger dealers in uae heat exchangers are devices that are used to transfer heat from one medium to another or from one liquid to another without the two fluids having to come into contact with each other. There are probably heat exchanger in your office building which heat transfer from hot water to the ventilation system in the winter and from the. The present work is directed towards the modeling of shell and tube parallel flow heat exchanger in solid works 2014 and setting up of flow simulation in solid works by inserting boundary.
Heat transfer lab manual pdf ht lab manual pdf notes. It can be operated as a parallel flow or as a counterflow heat exchanger. The flow in a heat exchanger can be arranged as parallel flow, counter flow, and cross flow. If the inline pdf is not rendering correctly, you can download the pdf file here. There are probably heat exchanger in your office building which heat transfer from hot water to the ventilation.
Entropy generation analysis of parallel and counterflow threefluid. Parallel flow heat exchanger and counter flow heat exchanger hmt tutorial 20 other subjects from ujjwal kumar sen all sfd and bmd tutorials. If we comnpare parallel and counterflow heat exchanger, for same heat exchange area and overall heat exchange coeficient the heat transferred in c view the full answer. Temperature profiles in a counterflow and b parallel flow single pass heat exchangers. Asee 2014 zone i conference, april 35, 2014, university.
This heat exchanger consists of two concentric pipes of different diameters. How lmtd of counter flow heat exchanger is greater than. Therefore, different types of heat exchangers have different effectiveness relations. Pdf a design of the control of the internal fluid temperature at the outlet of a parallelflow heat exchanger by manipulating the inlet external fluid. The wet heat exchanger has a higher effectiveness in counter flow than parallel flow. Here, we illustrate the development of the effectiveness relation for the doublepipe parallel flow heat exchanger. However ordinary heat exchangers might be extremely dissimilar in design and construction and might be of the single or twophase kind, their modes of operation and efficiency are largely established by the direction of the fluid flow inside the exchanger. Aircooled heat exchangers are usually used when the heat exchanger outlet temperature is at least 20 of above the maximum expected ambient air temperature. This study was done by changing the parallel flow configuration into counter flow configuration under laminar flow regime. Pdf design and development of parallel counter flow. Pdf analysis of a parallelflow heat exchanger with a heat source.
Combining each of these resistances in series gives. Plate heat exchanger working principle, how a plate heat. Pdf material selection and fluid flow analysis of parallel flow. However ordinary heat exchangers might be extremely dissimilar in design and construction and might be of the single or twophase kind, their modes of operation and efficiency are largely established by the. This engineering calculator will determine a number of variables for the most common arrangements or flow paths within heat exchangers. Here, we illustrate the development of the effectiveness. Heat exchangers are typically classified according to flow arrangement and type of construction.
If the heat exchanger is located at the inlet or discharge of a blower with a pulsating flow, such as a roots type rotary lobe blower, the heat exchanger must be protected from the pulsation by a chambered silencer. Shellandtube heat exchanger sthe, where one flow goes along a bunch of tubes and the other within an outer shell, parallel to the tubes, or in crossflow fig. Heat exchangers have widespread industrial and domestic applications. Parallel and counter flow designs heat exchangers engineers.
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