A heat exchanger is a device in which heat is transferred from one fluid to another. Indranil ghosh iit kharagpur july 2018 lecture 32 20. They are widely used in space heating, refrigeration, air conditioning, power plants, chemical plants, petrochemical plants, petroleum refineries, natural. Mod04 lec17 heat transfer corelations for flow across tube banks mod04 lec18 momentum and heat transfer analogies mod04 lec19 boundary layer heat transfer. These exchangers are composed of many thin, slightly separated plates that have very large surface areas and small fluid flow passages for heat transfer. They are widely used in space heating, refrigeration, air conditioning, power plants, chemical plants, petrochemical plants, petroleum refineries, natural gas processing and. Although heat exchangers come in every shape and size imaginable, the construction of most heat exchangers fall into one of two categories. Objectives recognize what is heat exchanger differentiate numerous types of heat exchanger, their classification and their applications know the heat transfer equipment terminologies know the primary consideration in the selection of heat exchangers. Platetype exchangers have typically 5mm channel size with more than.
They can operate at high pressures, are easy to clean and can be made of a wide variety of. Nptel chemical engineering chemical engineering design ii joint initiative of iits and iisc funded by mhrd page 5 of 41 table 1. This type of heat exchanger, also referred to as a surface heat exchanger, can be further classi. Heat transfer nptel online videos, courses iit video. Contents preface li acknowledgments liii author lv chapter1 heatexchangers. The hot fluid gets cooled, and cold fluid is heated. Shell shell is the container for the shell fluid and the tube bundle is placed inside the shell. A counterflow heat exchanger is the most efficient flow pattern of the three. Plate fin heat exchangers pfhe, types, construction. The fluids may be separated by a solid wall to prevent mixing or they may be in direct contact.
Nptel video lectures, iit video lectures online, nptel. The resulting heat transfer rate through the fin will be q fin ka c dt dx x0 v tanh ml case 3. Base your calculation on the outside area of the inside pipe. Shell and tube exchanger for two phase heat transfer 2. Introduction of heat exchangers piping analysis youtube. In this type of exchangers the tube sheet is welded to the shell and no relative movement between the shell and tube bundle is possible figure 1. Fin is finite in length and also loses heat by convection from its tip end not insulated conduction heat transfer at x l is equal to convection heat transfer from tip i. A heat exchanger is a heat transfer device that exchanges heat between two or more process fluids. Such devices for efficient transfer of heat are generally called heat exchanger. Direct contact heat exchangers, also known as mix exchangers, are devices where both fluids undergo a complete physical mixture. Heat exchanger and its types engineering solutions. Calculate the heat transfer area of the double pipe heat exchanger in the lab. Fundamentals and design analysis usb media storage type.
A heat exchanger is a piece of equipment built for efficient heat transfer from one medium to another. The spiral heat exchanger is a compact type heat exchanger. Heat transfer data for spiral heat exchangers is empirically correlated using a conventional dittusboelter type relationship for turbulent flow. A recuperative heat exchanger has separate flow paths for each fluid and fluids flow simultaneously through theexchanger exchanging heat across the wall separating the flow paths. There are different types of compact heat exchanger design available. Applications of heat exchangers heat exchangers prevent car engine overheating and increase efficiency heat exchangers are used in industry for heat transfer. Since all heat exchangers considered in this experiment have a single pass for both the hot and cold fluids, the discussion below is limited to singlepass heat exchangers. 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. In parallel flow, both the hot and cold fluids enter the heat exchanger at the same end and. A heat exchanger is a device that is used to transfer thermal energy enthalpy. Different types and sizes of heat exchangers are used in steam power plants, chemical processing units, building heating and air conditioning, house hold. The double pipe heat exchanger is one heat exchanger pipe inside another larger pipe for either counter flow or parallel flow pattern. This heat exchanger has application in preheating for steam power plants, blast furnaces and oxygen producers etc. What is the difference between a recuperative and a.
Advances in gasket and brazing technology have made the plate type heat exchanger increasingly practical. The shell and tube heat exchanger in the photo above has about twelve times the efficiency than a hypothetical singletube heat exchanger of the same size. Heat exchangers are extensively used in industry due to. One example of this type is the double pipe exchanger. Pdhonline course m371 2 pdh shell and tube heat exchangers. Three basic types of heat exchanger the simple parallel or counter. The heat exchanger is an equipment that allows heat transference between two fluids at different temperatures. Mar 11, 2018 size of the cooling tower can vary from a small rooftop unit to huge hyperboloid units as used in nuclear power stations. Qualitative dependence of the fluid temperature on position inside a singlepass heat exchanger is shown in fig. Two main types of heat exchangers the two main types of heat exchangers that exist. For example, heat exchanger designs can employ multiple flow passes and arrangements e. Compact heat exchangers, enhancement of heat transfer, extended surface or fin, fundamental of extended surface heat transfer, fin tube heat exchanger. When flow of fluid is periodic then it is known as regenerative type heat exchangers.
Many types of heat exchangers have been developed for use in steam power plants, chemical processing plants, building heat and air conditioning systems. A heat exchanger can have several different flow patterns. Optimal design of double pipe heat exchanger structures. The devices that are used to facilitate heat transfer between two or more fluids at different temperatures are known as heat exchangers. Balanced counter flow heat exchanger assuming and cc, then the lmtd becomes undefined as. The heat exchange duty a llows calculation of the log mean. The selection of a heat exchanger depends on many factors including capital and operating costs, fouling, corrosion tendency, pressure drop, temperature ranges, and safety issues tolerance to leakage. Shell and tube heat exchanger shell and tube heat exhangers are one of the most common heat exchange equipment found in all plants. Based on the type of flow, calculate log mean temperature difference. This is composed of multiple, thin, slightlyseparated plates that have very large surface areas and fluid flow passages for heat transfer. Plate heat exchanger another type of heat exchanger is the plate heat exchanger. Bem, aem, nen provides maximum heat transfer area for a given shell and tube diameter. It leads to the lowest required heat exchanger surface area because the log mean temperature drop is the highest for a counterflow.
Gaitonde, department of mechanical engineering, iit. Pdf heat transfer and exergy analysis of a spiral heat. Types of heat exchanger, process design of shell and tube heat exchanger, condenser, and reboilers. Mechanical design standards of shell and tube heat exchangers mechanical design of heat exchangers includes design of various pressure and nonpressure parts. Heat exchanger problem calculation lmtd and effectiveness. Conduction and convection are the two way which are more concern in case of heat exchangers. Types of heat exchanger basic of heat transfer introduction to heat exchanger. Gaitonde, department of mechanical engineering, iit bombay. Introduction, types driers, design consideration of driers process design of heat exchanger.
Counterflow, parallel flow, and crossflow are common heat exchanger types. Reason for heat exchangers a heat exchanger is a piece of equipment built for efficient heat transfer from one medium to another hot and cold fluid. Background, application, classification, common terminologies. The structural rigidity and satisfactory service of heat. May 04, 2009 heat transfer 1 heat exchangers heat transfer heat exchanger types of heat exchangers heat exchangers are classified according to flow arrangement and type of construction. Types of heat exchanger construction although heat exchangers come in every shape and size imaginable, the construction of most heat exchangers fall into one of two categories. View notes mod1 from ech 143 at hanoi university of mining and geology. Heat transfer nptel online videos, courses iit video lectures. This stacked plate arrangement can be more effective, in a given space, than the shell and tube heat exchanger. Nptel online videos, courses iit video lectures well organized. Heat exchangers are devices that facilitate the exchange of heat between two fluids that are at different temperatures while keeping them from mixing with each other. Two types of flow arrangement are possible in a doublepipe heat exchanger. Based on chapter 11 in the textbook of cengel and ghajar 4th edition. The first type of a heat exchanger is called the recuperative type, in which heat are exchanged on either side of a dividing wall by fluids.
Apr 19, 2012 introduction a heat exchanger is a device in which two fluid streams, one hot and another cold, are brought into thermal contact in order to effect transfer of heat from the hot fluid stream to the cold. The plateandframe heat exchanger design consists of stacked of corrugated plates which are bonded together. Two approaches to heat exchanger design that will be discussed are the lmtd method and the effec tiveness ntu method. This paper investigates the design optimization of double pipe heat exchanger using mathematical programming. 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. However, there is a disadvantage to smaller tubes if the fluid in your application is very viscous or has particulates, it can foul up the tube and undermine the heat transfer process. Heat exchangers are normally classified depending on the transfer process occurring in them.
There are many types of heat exchangers applied in the process industry. If the boiler is undersized, it may not generate enough heat in winter. The heat is transferred from the hot fluid to the metal isolating the two fluids and then to the cooler fluid. Heat exchangers are used in ac and furnaces the closedtype. Heat transfer heat exchanger types of heat exchangers. Nptel chemical engineering chemical engineering design ii joint initiative of iits and iisc funded by mhrd page 2 of 21 lecture 1.
A gasoil central heating boiler heat generator is like the engine of a car, this provides the heat that the facility needs to warm itself up. Aregenerative heat exchanger has a single flow path, which the hot. Iits and iiscs free open online web and video courses for science and engineering under nptel similar websites like nptel. John richard thome ltcm sgm epfl heat transfer heat exchanger design 1er mars 2008 4 41. Heat exchangers a device whose primary purpose is the transfer of energy between two fluids is named a heat exchanger.
Ironore is one of the most mineral existing in nature, and natural iron ore can be divided into different categories such as hematite, magnetite, limonite, and so on. In this type the same space is occupied by the hot and cold fluid between which heat is exchanged. Different types of heat exchangers are shown in figure 42. Understanding heat exchangers types, designs, applications. It provides relatively large area of heat transfer for a given volume of the equipment.
This type provides a large heat transfer surface in a small space. They are the most versatile type of heat exchangers. Heat exchangers have widespread industrial and domestic applications. Thermal design of a shell and tube heat exchanger typically includes the determination of heat transfer area, number of tubes, tube length and diameter, tube layout, number of shell and tube passes, type of heat exchanger fixed tube sheet, removable tube bundle etc, tube pitch, number of baffles, its type and size, shell and tube side pressure drop etc. Another type of heat exchanger is the plate heat exchanger. A channel curvature component is added in order to take into account the somewhat improved heat transfer generated by secondary flow effects. Mod07 lec30 various types of compact heat exchangers. These types of heat exchangers are typically used to accommodate the limitations of an application, such as space, budget costs, or temperature and pressure requirements. General classification of heat exchangers is shown in the figure 1. However, in the real and practical sense, we seldom see such huge sized cooling towers and mostly smallsized cooling towers are common in use for discharging heat generated by air conditioning systems.
Introduction to thermal and hydraulic aspects, pressure drop and heat transfer, sizing and rating. With this configuration the fluid is spread out over the multiple plates. The size of the boiler is matched to the size of the facility. Overall heat transfer coefficient for doublepipe heat. Heat exchangers are used in both cooling and heating processes. Fixed tubesheet exchanger nonremovable tube bundle. Heat exchangers are used in ac and furnaces the closed type exchanger is the most popular one.
Heat transfer in heat exchangers involves convection in each fluid and conduction through the wall separating. A piece of equipment built for efficient heat transfer from one medium to another. Aloke kumar ghosal, department of chemical engineering, iit guwahati. The simplest and cheapest type of shell and tube exchanger is with fixed tube sheet design. A heat exchanger is a system used to transfer heat between two or more fluids.
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