How to design shell and tube heat exchanger in excel spreadsheet. Pdf this paper provides the solution to the problem of defining thermal. The basic design equation and overall heat transfer coefficient the basic heat exchanger equations applicable to shell and tube exchangers were developed in chapter 1. Pdf spreadsheet addin for heat exchanger logarithmic mean.
The amount of btus given a specific flow rate and delta t. Heat unit conversions, multilayer conductivity, convective heat transfer, 2dimensional heat transfer, cooling fins, heat exchangers, and heat radiation. Pdf available in journal of heat transfer 1299 september 2007 with 42,867 reads. Counterflow heat exchangers the relation above for the log mean temperature difference is developed using a. In order to use the heat exchanger design equation to calculate a required heat transfer area, a value is needed for the heat transfer rate, q. The heat transfer rate, q, can be calculated in a preliminary heat exchanger design spreadsheet if the flow rate, heat capacity and temperature change are known for either the hot fluid or the cold fluid. The heat exchanger must be isolated from system vibrations using flexible piping connections and isolation pads on the mounting feet. These deposits may be due to sedimentation, crystallization, organic and biological.
Use to determine how overall heat transfer rate, q, depends on. 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. The ratio of the heat transfer surface area on one side of the heat exchanger to the volume is used as a measure of compactness. Parallelflow heat exchanger logmean temperature difference. A weaker fouling layer of particulate fouling, or crystallization fouling combining. The heating is to be accomplished by passing hot engine oil, which is available at. Particulate fouling, taking place due to the accumulation of suspended particles in the fluid stream on the surface of the heat exchanger. Furthermore, dont touch it until complete cooldown to the normal temperature after the shutdown. Heat exchanger design free download as powerpoint presentation. 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. Make a more detailed estimate of the overall heat transfer coefficient, u, based on the preliminary heat exchanger configuration. The resulting blend is left in a blending tank for a sufficient period of time to allow for. Heat exchanger problem calculation lmtd and effectiveness. Brazed plate heat exchanger and tubeintube heat exchangers are commonly used in the water heating heat pumps for sanitary and space heating applications.
Nomenclature a surface area of the heat exchanger, m 2 c. In contrast to the parallel flow heat exchanger, the counter flow heat exchanger can have the hottest coldfluid. When the heat exchanger is under running or pressurizing, never unscrew any of the tightening bolts. Then one unknown parameter can be calculated for the other fluid. The basic component of a heat exchanger can be viewed as a tube with one fluid running through it and another fluid flowing by on the outside. The thermal and hydraulic performance of heat exchangers decreases continuously with time due to fouling, which is defined as the formation of deposits on heat transfer equipment.
Specifying shellandtube heat exchangers understand what heat exchanger design specialists need to know and remember, you know your process best asif raza shellandtube heat exchangers are one of the most important and commonly used process equipment items in the chemical process industries cpi. The basic designs for heat exchangers are the shellandtube heat exchanger and the plate heat exchanger, although many other configurations have been developed. Fintube heat exchanger performance for different louver angles 119 the flow and heat transfer phenomena in a round tube heat exchanger with and without louvered fins are analysed numerically. Heat transfer excel calculations a pdh online course for.
Specification of tube parameters size, layout, pitch and material. The threedimensional computational domain with louvers is. Heat exchangers can be classified into four types, according to. Heat transferheat exchangers blogs engineering excel templates. Cengel, 2007 there are many applications for heat exchanger in industrial field. Heat exchangers differ from mixing chambers in that they do not allow the two fluids involved to mix. This rate of heat flow can be calculated if the flow rate of one of the fluids is known along with its specific. Balanced counter flow heat exchanger assuming and cc, then the lmtd becomes undefined as. The heat exchanger having a surface area density on anyone side greater than about 700 m2m3 is known as a compact heat exchanger. Shell and tube heat exchanger partial differential equations in the analysis of a heat exchanger, or any heat transfer problem, one must begin with an energy balance. As its name implies, this type of heat exchanger consists of a shell a large vessel. Pasteurizing milk is one type of heat exchanger using in food.
Combining each of these resistances in series gives. The second heat transfer process is convection, or heat transfer due to a flowing fluid. Numerous articles have been published regarding the advantages of compact heat exchangers. Pdf heat exchangers are used to transfer heat between two sources. Combining each of these resistances in series gives o. Shell and tube type heat exchanger, indirect contact type heat exchanger. Jul 01, 2016 heat can flow only from hotter to cooler fluids, as per the second law of thermodynamics.
Solving a traditional shell and tube heat exchanger problem. In this report, a typical heat exchanger problem is presented and shown how it can be solved with a numerical approach. How to calculate the efficiency or effectiveness of a plate. Dec 21, 2014 in order to use the heat exchanger design equation to calculate a required heat transfer area, a value is needed for the heat transfer rate, q. Design a double pipe heat exchanger with bare inner multitubes that can be used to cool engine oil with cold sea water. Heat can flow only from hotter to cooler fluids, as per the second law of thermodynamics. This rate of heat flow can be calculated if the flow rate of one of the fluids is known along with its specific heat and the required temperature change for that fluid. Lesson30 numerical problems related to heat exchanger. Heat exchanger design and heat transfer coefficients archives. Therefore, it can produce the most effective performance from the compact size. Heat exchangers are devices that transfer energy between fluids at. Shell and tube heat exchanger the traditional heat balance model is utilized based on the assumption that the amount of heat given up by the hot fluid is equal to the amount of heat received by the cold fluid, as shown in the equation 3. Fluid engine oil sea water inlet temperature, c 65 20 outlet temperature, c 55 25 heat load, kw 117.
The overall heat transfer coefficient of the exchanger is 300 wm2 k, and the area for heat transfer is 15. According to flow layout, heat exchangers are grouped in. Heat load formula definition, explanation, formula and. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. However, the term is commonly used to equipment in which two process streams exchange heat with each other. If the transfer factor, f, between the melt and the sheet is. Jin, shenghan and hrnjak, pega, a method to combine local heat transfer and flow. Convection is the process of heat transfer by displacing the macroscopic elements of a. Spreadsheet addin for heat exchanger logarithmic mean temperature difference correction factor article pdf available in international journal of computer applications 445.
Equation 7 is for clean or unfouled heat exchanger surfaces. T 2 represent the temperature difference between the two fluids at the two ends inlet and outlet of the heat exchanger. Here, we will cite only those that are immediately useful for design in shell and tube heat exchangers with sensible heat transfer on the shellside. Counterflow heat exchangers the relation above for the log mean temperature difference is developed using a parallelflow heat exchanger, but we can show. Minimum amount of cooling water vibration free can provide internal demister low air side pressure drops cataract steel. In contrast to the parallel flow heat exchanger, the counter flow heat exchanger can have the hottest coldfluid temperature greater than the coldest hotfluid temperatue. Estimate the pressure drop across the heat exchanger. The two most common heat exchanger design problems are those of rating and sizing. A typical heat exchanger, usually for higher pressure applications up to 552 bars, is the shell and tube heat exchanger. The term heat exchanger applies to all equipment used to transfer heat between two streams. T temperature difference, k c specific heat, jkgk k heat transfer coefficient, wm. Proceedings of the 2014 international conference on. This is done by combining the thermal death time data with the temperaturetime.
Selection of heat transfer models and fouling coefficients for shell side and tube side. Basics of heat transfer this lecture is intended to refresh the post graduate students memory about the basics of heat transfer regarding the various modes of heat transfer, analogy between heat transfer and electric circuits, combined modes of heat transfer and the overall heat transfer coefficient. Properties of air and water useful for convection calculations. Proceedings of the 2014 international conference on mechanics. The first transparent plate was made from a flat polycarbonate sheet lexan 9034.
Local plate heat exchanger calculation and the associated flowchart for. According to awad 2011, these phenomena can be divided into. Shell and tube heat exchangers basic calculations pdh online. Shellandtube heat exchanger sthe, where one flow goes along a bunch of tubes and the other. In convection heat transfer, the heat is moved through bulk transfer of a nonuniform temperature fluid. Selection of heat exchanger tema layout and number of passes. Quiz once you finish studying the above course content, you need to take a quiz to obtain the pdh credits. I am new to this website, i wanted to share a few spreadsheets, dont know whether this where i should share the file or not. However, it is possible to obtain q by combining eq. If it is too high, revise the heat exchanger configuration until the pressure drop is acceptable.
When heat exchanger handles steam and other fluid of high temperature, it has hazard of burns. Aug 10, 2011 the basic heat exchanger design equation is. Determine the heat load in the electric convector in which the rate of mass flow is 5. A sthe is the most common type of heat exchanger in oil re fineries and other large chemical processes, and is suited for higherpressure applications. Chapter 5 heat exchangers faculty of engineering and.
In food industrial, heat exchanger is being used to transfer heat from hot to cold or vice versa. Heat transfer equation sheet heat conduction rate equations fouriers law heat flux. Combine both of these to write the change in temperature. Examples are water cooling towers and jet condensers in. A fixedtube sheet heat exchanger has straight tubes that are secured at both.
Q the rate of heat transfer between the two fluids in the heat exchanger in buthr kjhr for s. 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. 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. John richard thome ltcm sgm epfl heat transfer heat exchanger design 1er mars 2008 6 41 the cross. Equation 7 is fo r clean or unfouled heat exchanger surfaces. Setting upper and lower design limits on tube length. Heat exchanger fouling and estimation of remaining useful life.
Pdhonline course m371 2 pdh shell and tube heat exchangers. Based on the type of flow, calculate log mean temperature difference, lmtd. The alternative channels maximises the heat transfer surface in a compact manner. The es extended surface heat exchanger is designed as a compressor intercooler with the ability to cool large volumes of air with. By combining the first law with fouriers law, we have eliminated. Counter flow heat exchangers are the most efficient of the three types. Heat exchangers are devices that regulate efficient heat transfer from one fluid to another. Heat conduction is the process of molecular heat transfer by microparticles molecules, atoms, ions, etc. If the overall heat transfer coefficient is expected to be 1.