A PROJECT REPORT ON
DESIGN OF PANNEL HEAT EXCHANGER FOR CHILLING UNIT
Patel Divyesh (140370119222)
Patel Himanshu (140370119225)
Patel Jainil (140370119228)
Patel Kevin (140370119235)
Parmar Darshan (140370119199)
In part fulfillment for the award of the degree
BACHELOR OF ENGINEERING
Mechanical Engineering Department
Parul Institute of Engineering & Technology
P.O. Limda, Ta. Waghodia,
Dist. Vadodara-391760, Gujarat, India.
Gujarat Technological University, Ahmedabad
Date: / /2017
This is to certify that the dissertation entitled “DESIGN OF PANEL HEAT EXCHANGER FOR CHILLING UNIT” has been carried out by
Patel Divyesh (140370119222)
Patel Himanshu (140370119225)
Patel Jainil (140370119228)
Patel Kevin (140370119235)
-561975353695 Parmar Darshan (140370119199)
Under my guidance in Partial fulfillment for the degree of Bachelor of Engineering in Mechanical (8thSemester) of Gujarat Technological University, Ahmadabad during the academic year 2017-18.
Prof. Deman Sahu
Project Guide (Internal) Prof. N. H. Gandhi
Prof. JALPA ZALAVADIYA
Head of the Department,
Department of Mechanical Engineering External Examiner
We have taken efforts in this project. However, it would not have been possible without the kind support and help of many individuals and organizations. We would like to extend our sincere thanks to all of them.
With immense pleasure we express my deep and sincere gratitude, regards and thanks to my project guide Prof. N. H. Gandhi for his excellent guidance, invaluable suggestions and continuous encouragement at all the stages of my project work. His wide knowledge and logical way of thinking have been of great value for us. As a guide he has a great influence on us, both as a person and as a professional.
We wish to express our warm and sincere thanks to Prof. JALPA ZALAVADIYA (Head of Department of Mechanical Engineering, PIET) for his support & the facilities provided by him in college.
I would like to express my special gratitude and thanks to industry persons for giving me such attention and time for manufacturing of the machine.
At last, we cannot forget our family members supporting us spiritually throughout our life and our friends without whom it was really not possible for us to do this dissertation. Finally, thank you to Parul Institute and all the other people who have supported us during the course of this work.
The primary objective of the project is to design a panel heat exchanger in order to increase overall heat transfer efficiency. In this project we use thin plates in order to increase the surface area for heat dissipation and due to that we get larger temperature difference that is all we want. Plate type heat exchanger is very compact compared to shell and tube heat exchanger due to that less floor area required in industry and also use in domestic purpose. This heat exchanger in working condition is exposed to the atmosphere so that rate of heat transfer is also increase.
TITLE PAGE NO
CHAPTER 1 INTRODUCTION 9
1.1 Introduction 9
1.2 Main challenges 10
1.3 Working principle 11
1.4 Application 12
CHAPTER 2 LITERATURE REVIEW 13
2.1 Introduction 13
2.2 Usage and Application of Heat exchanger 13
2.3 Types of Heat Exchanger 14
2.4 Literature review based on research paper 21
CHAPTER 3 PROJECT PLANNING 24
3.1 Project Planning table 24
CHAPTER 4 METHODOLOGY 26
CHAPTER 5 COMPONENTS OF PROJECT 28
5.1 Mild steel panels and pipe 28
5.2 Induction heater 30
5.3 Thermometer 31
5.4 Pump 32
5.5 Structure 33
5.6 Supporting Post 34
5.7 Calculations 34
CHAPTER 6 TESTING 36
6.1 Procedure 36
CHAPTER 7 TOOLS AND MACHINE USED 38
7.1 Tools and Equipments 38
7.2 Process involve 39
CHAPTER 8 CONCLUSION 40
8.1 Conclusion 40
8.2 Future scope 40
LIST OF FIGURES
FIG NO. FIGURE NAME PAGE NO.
5.1.6 Heat flow system
Tubular heat exchanger
Shell and tube heat exchanger
Spiral heat exchanger
Gasketed late heat exchanger
Spiral plate heat exchanger
Direction of flow of heat
Arrangement of plates
LIST OF TABLES
TABLE NO TABLE NAME PAGE NO.
2 Project planning 16
Heat exchangers are devices that provide the transfer of thermal energy between two or more fluids at different temperatures. Shell and tube heat exchangers are the most versatile type of heat exchangers. They are used in the process industries, in conventional and nuclear power stations and they are proposed for many alternative energy applications. The enhancement in heat transfer rate between two or more fluids in heat exchanger is mainly achieved by optimizing the design of heat exchanger and operational parameters.
Heat flow system
Optimizing the operational parameters play a key role in the enhancement of heat transfer rate after the design of heat exchanger. The transfer of heat to and from process fluids is an essential part of most chemical processes. The most commonly used type of heat-transfer equipment is the ubiquitous shell and tube heat exchanger; the design of which is the main subject of this report. The word “exchanger” really applies to all types of equipment in which heat is exchanged but is often used specifically to denote equipment in which heat is exchanged between two process streams. Exchangers in which a process fluid is heated or cooled by a plant service stream are referred to as heaters and coolers. If the process stream is vaporized the exchanger is called a vaporizer if the stream is essentially completely vaporized; a reboiler if associated with a distillation column; and an evaporator if used to concentrate a solution. The term fired exchanger is used for exchangers heated by combustion gases, such as boilers, other exchangers are referred to as “unfired exchangers”.
The project work subject is one, in which actually we are leaning the theoretical concepts in practical way. Also the practical experience is one of the aims of this subject. For a developing industry these operating performed and the parts or components produced should have its minimum possible production cost, then only the industry runs profitably.
To Design and fabricate a shell and tubes heat exchanger with bell’s method to check and enhance the efficiency and learn the method. Modification have been incorporated, wherever required, to suit local material availability and fabrication limitation keeping in view economical aspect.
1.2 Main Challenges are:
Design of plate heat exchanger
Design economy and optimization
Fabrication and testing
1.3 WORKING PRINCIPLE
1.3.1 Flow diagram
Heat exchangers with only one phase on each side can be called one-phase or single-phase heat exchangers. As we start pump water with start flowing through shell and another fluid which need to be cooled flow in to pipe, as a result heat transfer with each other.
Industrial cooling application
Nuclear systems cooling
Space and Defense
Cooling of Microchips
Heat exchanger is one of devices that is convenient in industrial and household application. These include power production, chemical industries, food industries, electronics, environmental engineering, manufacturing industry, and many others. It comes in many types and function according to its uses. So what exactly heat exchanger is? Heat exchanger is a device that is used to transfer thermal energy between two or more fluids, between a solid surface and a fluid at different temperatures and in thermal contact. There are usually no external heat and work interactions. In most heat exchangers, heat transfer between fluids takes place through a separating wall or into and out of a wall in a transient manner. (Shah R.K., 2003)
This chapter will discuss about the uses and application of shell and tube heat exchanger, type of heat exchangers, and shell and tube heat exchanger.
2.2 USES AND APPLICATIONS OF HEAT EXCHANGER
Heat exchangers are used to transfer heat from one media to another. It is most commonly used in space heating such as in the home, refrigeration, power plants and even in air conditioning. It is also used in the radiator in a car using an antifreeze engine cooling fluid. Heat exchangers are classified according to their flow arrangements where there are the parallel flow, and the counter flow. Aside from this, heat exchangers also have different types depending on their purpose and how that heat is exchanged.
But the fact is that there are heat exchangers even in the circulation system of fishes and whales. The veins of these animals are intertwined such that one side is carrying cold blood and the other has cold blood. As a result, these species can prevent heat loss especially when they are swimming in cold water. In some whales, the heat exchanger can be found in their tongues. When it comes to the manufacturing industry, heat exchangers are used both for cooling and heating. Heat exchangers in large scale industrial processes are usually custom made to suit the process, depending on the type of fluid used, the phase, temperature, pressure, chemical composition and other thermodynamic properties. (Kakac, S. 2002) Heat exchangers mostly can be found in industries which produce a heat stream.
In this case, heat exchangers usually circulate the output heat to put it as input by heating a different stream in the process. The fact that it really saves a lot of money because when the output heat no longer needed then it can be recycled rather than to come from an external source as heat is basically recycled. When used in industries and in the home, it can serve to lower energy costs as it helps recover wasted heat and recycle it for heating in another process. Typically, most heat exchangers use fluid to store heat and heat transfer can take the form of either absorption or dissipation. For instance, heat exchangers are used as oil coolers, transmission and engine coolers, boiler coolers, waste water heat recovery, condensers and evaporators I refrigeration systems. In residential homes, heat exchangers are used for floor heating, pool heating, snow and ice melting, domestic water heater, central, solar and geothermal heating. Of course, heat exchangers have different designs which depend on the purpose it is intended for. Brazed heat exchangers, a collection of plates which are brazed together, are used for hydronic systems like swimming pools, floor heating, snow and ice melting. The shell and coil heat exchanger design is best for areas with limited spaces as it can be installed vertically. Of course, for the highly industrial process, the shell and tube heat exchanger is the perfect solution.
2.3 TYPE OF HEAT EXCHANGERS
In industries, there are lots of heat exchanger that can be seen. The types of heat exchanger can be classified in three major constructions which are tubular type, plate type and extended surface type.
2.3.1 Tubular Heat Exchangers
The tubular types are consists of circular tubes. One fluid flows inside the tubes and the other flows on the outside of the tubes. The parameters of the heat exchanger can be changed like the tube diameter, the number of pitch, tube arrangement, number of tubes and length of the tube can be manipulate. The common type of heat exchanger lies under these categories are double-pipe type, shell-and-tube type and spiral tube type.
2.3.1 Tubular Heat Exchanger
The tubular heat exchangers can be designed for high pressure relative to the environment and high-pressure difference between the fluids. These exchangers are used for liquid-to-liquid and liquid-to-vapor phase. But when the operating temperature or pressure is very high or fouling on one fluid side, it will used gas-to-liquid and gas-togas heat transfer applications.
220.127.116.11 Double-Pipe Heat Exchanger
According to Sadic Kakac, a double-pipe heat exchanger consists of smaller and larger diameter pipe where the smaller pipe fitted concentrically into the larger one in purpose to give direction to the flow from one section to another. One set of these tubes includes the fluid that has to be cooled or heated. The second fluid runs over the tubes being cooled or heated in order to provide heat or absorb the heat. A set of tubes is the tube bundle and it can be made up of several types of tubes such as longitudinally plain, longitudinally finned, and more. If the application requires an almost constant wall temperature, the fluids may flow in a parallel direction. It’s easy to clean and convenient to disassemble and assemble. The double-pipe heat exchanger is one of the simplest. Usually, it is used for small capacity applications because it is so expensive on a cost
per unit area basis.
18.104.22.168 Shell-and-Tube Heat Exchanger
This exchanger is built of a bundle of round tubes mounted in a large cylindrical shell with the tube axis parallel to the shell to transfer the heat between the two fluids. The fluid flows inside the tubes and other fluid flows across and along the tubes. But for baffled shell-and-tube heat exchanger the shell side stream flows across between pairs of baffles and then flows parallel to the tubes as it flows from one baffle compartment to the next. This kind of exchanger consists of tubes, shells, front-end head, rear-end head, baffles and tube sheets. The different type of shell-and-tube heat exchangers depends on different application.
2.3.2 Shell and Tube Type Heat Exchanger
Usually in chemical industry and process application, it is used as oil-coolers, power condensers, preheaters in power plants and also steam generators in nuclear power plants. The most common types of shell-and-tube heat exchanger are fixed tube sheet design, U-tube design and floating-head type. Cleaning this heat
exchanger is easy. Instead of easily cleaning, it is also low in cost. But among all tube bundle types, the U-tube is the least expensive because it only needs one tube sheet. Technically, because of its construction in U shape, the cleaning is hardly done in the sharp bend. An even number of tube passes only can be achieved. The shows the type of shell-and-tube heat exchanger.
22.214.171.124 Spiral-Tube Heat Exchanger
A spiral heat exchanger is a helical or coiled tube configuration. It consists of spirally wound coils placed in a shell or designed as co-axial condensers and co-axial evaporators that are used in refrigeration systems. The heat transfer coefficient is higher in a spiral tube than in a straight tube. Since the cleaning is impossible, the spiral tubes are suitable for thermal expansion and clean fluids. The biggest advantage of the spiral heat exchanger is its efficient use of space. A compact spiral heat exchanger can lower costs, while an oversized one can have less pressure drop, higher thermal efficiency, less pumping energy, and lower energy costs. Spiral heat exchangers are frequently used when heating fluids that have solids and therefore often foul the inside of the heat exchanger. Spiral heat exchangers have three types of flow arrangements. Firstly, the spiral flow and cross flow has one fluid in each.
2.3.3 Spiral Heat Exchanger
The spiral flow passages are welded at each side and this type of flow is good for handling low density gases which pass through the cross flow. This can be used for liquid-to-liquid applications if one fluid has a much greater flow rate than the other. A second type is the distributed vapor and spiral flow. The coolant moves in a spiral and exits through the top. The hot gases that enter will leave as condensate out of the bottom outlet. The third type is the countercurrent flow where both of the fluids will flow in opposite directions and are used for liquid-to-liquid applications. The spiral heat exchanger is good for pasteurization, heat recovery, digester heating, effluent cooling, and pre-heating.
2.3.2 Plate Heat Exchangers
A second type of heat exchanger is a plate heat exchanger. It has many thin plates that are slightly apart and have very large surface areas and fluid flow passages that are good for heat transfer. This can be a more effective heat exchanger than the tube or shell heat exchanger due to advances in brazing and gasket technology that have made this plate exchanger more practical. Large heat exchangers are called plate and frame heat exchangers and there allow for periodic disassembly, cleaning, and inspection. There are several types of permanently bonded plate heat exchangers like dip brazed and vacuum brazed plate varieties, and they are often used in refrigeration. These heat exchangers can further be classified as gasketed plate, spiral plate and
126.96.36.199 Gasketed Plate Heat Exchangers
A gasketed plate heat exchanger consists of a series of thin plates that have wavy surface which function as separating the fluids.
2.3.4 Gasketed Plate Heat Exchanger
The plates come with corner parts arranged so that the two media between which heat is to be exchanged flow through interchange exclaim spaces. Appropriate design and gasketing permit a stack of plates to be held together by compression bolts joining the end plates. Gaskets prevent leakage to the outside and direct the fluids in the plates as desired. The flow pattern is generally chosen so that the media flow countercurrent to each other. Since the flow passages are quite small, strong eddying gives high heat transfer coefficients, high pressure drops, and high local shear which minimizes fouling. These exchangers provide a relatively compact and lightweight heat transfer surface. Gasketed plate are typically used for heat exchange between two liquid streams. This type can be found in food processing industries because of the compatibility to be cleaned easily and sterilized as it
188.8.131.52 Spiral Plate Heat Exchanger
Spiral heat exchangers are formed by rolling two long, parallel plates into a spiral using a mandrel and welding the edges of adjacent plates to form channels. The distance between the metal surfaces in both channels is maintained by means of distance pins welded to the metal sheet. The two spiral paths introduce a secondary flow, increasing the heat transfer and reducing fouling deposits. These heat exchangers are quite compact but are relatively expensive due to the specialized fabrication. The spiral heat exchanger is particularly effective in handling sludges, viscous liquids, and liquids with solids in suspension including slurries.
2.3.5 Spiral Plate Heat Exchanger
The spiral heat exchanger is made in three main types which differ in the connections and flow arrangements. Type ? has flat covers over the spiral channels. The media flow countercurrent through the channels via the connections in the center and at the periphery. This type is used to exchange heat between media without phase changes such as liquid-liquid, gas-liquid, or gas-gas. One stream enters at the center of the unit and flows from inside outward. The other stream enters at the periphery and flows towards the center. Thus, the counter flow is achieved. Type ?? is designed for crossflow operation. One channel is completely seal welded, while the other is open along both sheet metal edges. The passage with the medium in spiral flow is welded shut on each side, and the medium in cross flow passes through the open spiral annulus. This type is mainly used as a surface condenser in evaporating plants. It is also highly effective as a vaporizer. Two spiral bodies are often built into the same jacket and are mounted below each other.
2.4 LITERATURE REVIEW BASED ON RESEARCH PAPER
Ahmerrais khan and sarfaraz khan focus on the various researches on Computational Fluid Dynamics (CFD) analysis in the field of heat exchanger. It has been found that CFD has been employed for the various areas of study in various types of heat exchanges Different turbulence models available in general purpose commercial CFD tools i.e. standard, realizable and RNG k ?? RSM, and SST k ?? in conjunction with velocity-pressure coupling schemes such as SIMPLE, SIMPLEC, PISO and etc. have been adopted to carry out the simulations. The quality of the solutions obtained from these simulations are largely within the acceptable range proving that CFD is an effective tool for predicting the behavior and performance of a wide variety of heat exchangers.
Philippe Wildi-Tremblay in his paper explains the procedure for minimizing the cost of a shell-and-tube heat exchanger based on genetic algorithms (GA). The global cost includes the operating cost (pumping power) and the initial cost expressed
in terms of annuities. He took some geometrical parameters of the shell-and-tube heat exchanger as the design variables and the genetic algorithm is applied to solve the associated optimization problem. It is shown that for the case that the heat duty is given, not only can the optimization design increase the heat exchanger effectiveness significantly, but also decrease the pumping power dramatically.
SiminWangJianWenYanzhong Li in his paper shows that the configuration of a shell-and-tube heat exchanger was improved through the installation of sealers in the shell-side. The gaps between the baffle plates and shell is blocked by the sealers, which effectively decreases the short-circuit flow in the shell-side. The results of heat transfer experiments show that the shell-side heat transfer coefficient of the improved heat exchanger increased by 18.2–25.5%, the overall coefficient of heat transfer increased by 15.6–19.7%, and the efficiency increased by 12.9–14.1%. Pressure losses increased by 44.6–48.8% with the sealer installation, but the increment of required pump power can be neglected compared with the increment of heat flux. The heat transfer performance of the improved heat exchanger is intensified, which is an obvious benefit to the optimizing of heat exchanger design for energy conservation.
A.Pignotti in his paper established relationship between the effectiveness of two heat exchanger configurations which differ from each other in the inversion of either one of two fluids. This paper provides the way by which if the effectiveness of one combination is known in terms of heat capacity rate ratio and NTUs then the effectiveness of the other combination can be readily known.
V.K. Patel and R.V. Rao explores the use of a non-traditional optimization technique; called particle swarm optimization (PSO), for design optimization of shell-and-tube heat exchangers from economic view point. Minimization of total annual cost is considered as an objective function. Three design variables such as shell internal diameter, outer tube diameter and baffle spacing are considered for optimization. Two tube layouts viz. triangle and Square are also considered for optimization. Four different case studies are presented to demonstrate the effectiveness and accuracy of proposed algorithm. The results of optimization using PSO technique are compared with those obtained by using genetic algorithm (GA).
W.J.Marner, A.E.Bergles and J.M. Chenoweth studied the tubular enhanced surfaces used in shell-and-tube heat exchangers. As an initial step, the subject is limited to single-phase pressure drop and heat transfer; however, both tube side and shell side flows are taken into consideration. A comprehensive list of commercial augmented tubes which may be considered for use in shell-and-tube exchangers is given, along with a survey of the performance data which are available in the literature. They discussed the standardized data format which uses the inside and outside envelope diameters as the basis for presenting the various geometrical, flow, and heat transfer parameters for all tubular enhanced surfaces.
G.N. Xie, Q.W. Wang, M. Zeng, L.Q. Luo carried out an experimental system for investigation on performance of shell-and-tube heat exchangers, and limited experimental data is obtained. The ANN is applied to predict temperature differences and heat transfer rate for heat exchangers. BP algorithm is used to train and test the network. It is shown that the predicted results are close to experimental data by ANN approach. Comparison with correlation for prediction heat transfer rate shows ANN is superior to correlation, indicating that ANN technique is a suitable tool for use in the prediction of heat transfer rates than empirical correlations.
3.1) PROJECT PLANNING TABLE: –
Month July August September October November December
Activity Problem Identification ?
Literature Survey ? ? ?
Components/ Mechanisms Identification ? ? ?
Design of Mechanisms ? ?
Report Writing ? ?
Month January February March April May
Activity Procurement & Manufacturing of Components ? ? ?
Assembly ? ?
Testing (Trial) ?
Trouble Shooting & Modification ? ?
Thesis Writing ? ?
The methodology is a process for implementation and developing the project. The goal and the successfulness of the project is depends on how the plans is conduct to achieve the result. Methodology is to describe the each step to accomplish the sequence of the flow work from the beginning until the result is obtained and success. All the results obtain were evaluated and improved till the best result came out and to be taken. This implementation would be and getting the worst result where try and error is happens here. Where any ideal decision may reconsider and repeating to satisfy the best result.
Phase to process developing and fabricating. Discuss about the theories review, calculation, project specifications and etc. In order to achieve all this, the following methods are to be followed closely during the execution of the project to achieve the objective.
Understand the objective of the project and search for the best result to solve the problem statement.
Study the literature review and analyze what implementation can be made to this project. All information gathered together from the various sources such as common internet website sources, journals, books, written articles, paper, blogs, video site and any medium and resources.
Study and analyze all information and data gathered from various sources and related to with objective of the project. Classify and to understand the project requirement.
Experimentation and simulation where certain experiments are needed to be done in order to collect and to take note the data and record for improvement.
Generate conceptual design and concept selection where meet the characteristic require and final conceptual design is obtain.
Phase to detail design process where concept will be enhanced and optimized if there is disability and problems to produce the final design.
Fabrication and implementations is happen here where it will be develop and brought to life from the detail design drawing that have chosen.
Next step is to test run whether the prototype can work properly and meet the objective. Thus, the problem found will be analyze and need to be rework.
The last process is product realization and verification where it will be send to presented and enter the competition whether the product achieve the goals of the project.
COMPONENT OF THE PROJECT
Experimental set-up consistst a plate type heat exchanger, insulated hot water storage tank, control valves, condensate steam bucket valve, pump, filter and appropriate instrumentation for collecting the data.
5.1 MILD STEEL PANELS AND PIPE
A plate heat exchanger is a type of heat exchanger that uses metal plates to transfer heat between two fluids. This has a major advantage over a conventional heat exchanger in that the fluids are exposed to a much larger surface area because the fluids spread out over the plates. This facilitates the transfer of heat, and greatly increases the speed of the temperature change. Plate heat exchangers are now common and very small brazed versions are used in the hot-water sections of millions of combination boilers. The high heat transfer efficiency for such a small physical size has increased the domestic hot water (DHW) flowrate of combination boilers. The small plate heat exchanger has made a great impact in domestic heating and hot-water. Larger commercial versions use gaskets between the plates, whereas smaller versions tend to be brazed.
5.1.1 Direction of the Flow of Heat
The concept behind a heat exchanger is the use of pipes or other containment vessels to heat or cool one fluid by transferring heat between it and another fluid. In most cases, the exchanger consists of a coiled pipe containing one fluid that passes through a chamber containing another fluid. The walls of the pipe are usually made of metal, or another substance with a high thermal conductivity, to facilitate the interchange, whereas the outer casing of the larger chamber is made of a plastic or coated with thermal insulation, to discourage heat from escaping from the exchanger.
The plate heat exchanger (PHE) is a specialized design well suited to transferring heat between medium- and low-pressure fluids. Welded, semi-welded and brazed heat exchangers are used for heat exchange between high-pressure fluids or where a more compact product is required. In place of a pipe passing through a chamber, there are instead two alternating chambers, usually thin in depth, separated at their largest surface by a corrugated metal plate. The plates used in a plate and frame heat exchanger are obtained by one piece pressing of metal plates. Stainless steel is a commonly used metal for the plates because of its ability to withstand high temperatures, its strength, and its corrosion resistance.
5.1.2 Arrangement of Plates
The plates are often spaced by rubber sealing gaskets which are cemented into a section around the edge of the plates. The plates are pressed to form troughs at right angles to the direction of flow of the liquid which runs through the channels in the heat exchanger. These troughs are arranged so that they interlink with the other plates which forms the channel with gaps of 1.3–1.5 mm between the plates. The plates are compressed together in a rigid frame to form an arrangement of parallel flow channels with alternating hot and cold fluids. The plates produce an extremely large surface area, which allows for the fastest possible transfer. Making each chamber thin ensures that the majority of the volume of the liquid contacts the plate, again aiding exchange. The troughs also create and maintain a turbulent flow in the liquid to maximize heat transfer in the exchanger.
5.2 Induction Heater
5.1.3 Induction Heater
The work coil, also known as the inductor, is the component in the induction heating system that defines how effective and how efficiently the work piece is heated. Work coils range in complexity from a simple helical (or solenoid) wound coil consisting of a number of turns of
copper tube wound around a mandrel to a coil precision machined from solid copper and brazed together. The work coil is used to transfer the energy from the induction heating power supply and work head to the work piece by generating an alternating electromagnetic field. The electromagnetic field generates a current that flows in the work piece as a mirror image to the current flowing in the work coil. As the current flows through the resistivity of the work
piece it generates the heat within the work piece from I²R losses. A second heating principle, hysteretic heating is also in effect when the work piece is a magnetic material such as carbon steel. Energy is generated within the work piece by the alternating magnetic field changing the
magnetic polarity within the work piece. Hysteretic heating occurs in the work piece only up to the Curie temperature (750° C for steel) when the material’s magnetic permeability decreases.
A thermometer is a device that measures temperature or a temperature gradient. A thermometer has two important elements:
(1) a temperature sensor in which some physical change occurs with temperature, and
(2) some means of converting this physical change into a numerical. Thermometers are widely used in industry to control and regulate processes, in the study of weather, in medicine, and in scientific research.
There are various principles by which different thermometers operate. They include the thermal expansion of solids or liquids with temperature, and the change in pressure of a gas on heating or cooling. Radiation-type thermometers measure the infrared energy emitted by an object, allowing measurement of temperature without contact. Most metals are good conductors of heat and they are solids at room temperature. Mercury is the only one in liquid state at room temperature, and has high coefficient of expansion. Hence, the slightest change in temperature is notable when it’s used in a thermometer. This is the reason behind mercury and alcohol being used in thermometer.
A pump is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical action. Pumps can be classified into three major groups according to the method they use to move the fluid: direct lift, displacement, and gravity pumps.
Pumps operate by some mechanism (typically reciprocating or rotary), and consume energy to perform mechanical work by moving the fluid. Pumps operate via many energy sources, including manual operation, electricity, engines, or wind power, come in many sizes, from microscopic for use in medical applications to large industrial pumps. Mechanical pumps serve in a wide range of applications such as pumping water from wells, aquarium filtering, pond filtering and aeration, in the car industry for water-cooling and fuel injection, in the energy industry for pumping oil and natural gas or for operating cooling towers. In the medical industry, pumps are used for biochemical processes in developing and manufacturing medicine, and as artificial replacements for body parts, in particular the artificial heart and penile prosthesis.
Single stage pump – When in a casing only one impeller is revolving then it is called single stage pump.
Our whole project will be set on the structure only. This is the main part of the projectA machine structure is a fixed constructed object which functions as part of some mechanized process or which performs mechanized processes independently.
The various types of machine structures may differ vastly from each other in appearance. These do not include structures built to shelter or enclose machinery; the machinery must be inextricably linked to the structure’s form.
5.6 OTHER COMPONENTS: –
Here, we are designing single flow multi pass heat exchanger.
Assuming, The Gas flow inside tubes and receive heat from hot gases at the rate of 800W and surrounded by air at ambient temperature at 30°C Inside and Outside heat transfer coefficient for heat exchanger material (MS) are Hi = 250 W/m2k and Ho =400 W/m2krespectively. Inlet temperature of hot water are 80°C for our project and outside temperature of air is 30°C. We need exit temp of the water at 40°C, so it can bearable with our specified material of the purifier, as well exit temp of air should be 50°C.
Q = 400 W
Hi = 250 W/m2K
Ho = 400 W/m2K
Overall heat transfer coefficient
1/Uo = Ro / Ri x (1/Hi + 1/Ho)
1/Uo = 0.035 / 0.03 x (1/250 + 1/400)
1 /Uo = 0.00758 W/m2K
Uo = 131.86 W/m2K
2.Length of tube:
?T1 = Th1 – Tc1
= 80 – 40
= 40 K
?T2 = Th2 – Tc2
= 50 – 30
= 20 K
LMTD = (?T1 – ?T2) / ln (?T1/ ?T2)
= 28.85 K
now, Q = Uo x Au x LMTD
Q = Uo x (Ao) x LMTD
400= 131.86 x (Ao) x 28.85
Ao= 0.1051 m2
Suppose if we want 4 number of plates then corresponding area,
A = 0.026275 m2
So, the appropriate length is L = 0.3m=300 mm
And width of the plate = 0.0875m = 87.5 mm
Here we consider thickness of the plate is = 6 mm
Here there is conduction and convection take place in the plates so that our thickness of the plate should be as minimum as possible because rate of heat transfer is inversely proportional to the thermal conduction resistance.
Q = ?T/ R
Here R= conduction resistance = t/K A
Here K = thermal conductivity of the mild steel
t = thickness of the plate
We designed and built a our model to work perfeclty. We list down here all our work, process and machine used in ous project.
Shearing the mild steel plate
Make hole with drill machine
Cutting the mild steel pipe with 20 mm dia
Welding the pipe with elbow and plates
welding the structure complete
Attach coupling with the pipe inlet ; outlet
attach the pump
arrange the water collector
time in sec hot water in hot water out cold water in cold water out
10 70.5 61.5 32.3 39.2
20 70.1 61.5 32.3 39.2
30 70 61.3 32.3 39
40 69.8 62.2 32.3 39.9
50 69.8 61.2 32.3 38.9
60 69.7 59.9 32.3 37.6
70 69.3 60.2 32.3 37.9
80 69.2 61.3 32.3 39
90 69.3 60.4 32.3 38.1
100 69.1 60.1 32.3 37.8
110 68.8 59.2 32.3 36.9
120 68.8 59.3 32.3 37
We are having approximately 8 to 9 degree temperature difference.
TOOLS AND MACHINE USED
In the design and construction of the project, the procedures followed to achieve a positive result are laid down in the preceding text. But first, a look at the operations and tools involved.
7.1 TOOLS AND EQUIPMENTS:-
7.2 PROCESSES INVOLVED:-
Compact heat exchangers are most widely used for heat transfer applications in industries. Plate heat exchanger is one such compact heat exchanger, provides more area for heat transfer between two fluids in comparison with shell and tube heat exchanger. Plate type heat exchangers are widely used for liquid-to-liquid heat transfer applications with high density working fluids. This study is focused on use of plate type heat exchanger for water as a working fluid. The main objective of this work is to find effects of these parameters on performance of plate heat exchanger with parallel flow arrangement. Use of plate heat exchanger is more advantageous than the tube type heat exchanger with same effectiveness, as it occupies less space
8.2 Future Scope
If we choose precise and big model, than it can be helpful in the handling real size problem.
High pressure and copper material can be used for perfect handling.
1 D. Q. Kern, “Process Heat Transfer”, McGraw-Hill Book Company, Int. ed. 1965.
2 V.K. Patel, R.V. Rao, “Design optimization of shell and tube heat exchanger using particle swarm optimization technique”, Applied Thermal Engineering 30 (2010) 1417-1425.
3 Hari Haran, Ravindra Reddy and Sreehari, “Thermal Analysis of Shell and Tube Heat ExChanger Using C and Ansys”, International Journal of Computer Trends and Technology (IJCTT) – volume 4 Issue 7–July 2013.
4 A. Pignotti, “Relation Between the Thermal Effectiveness of Overall Parallel and Counter flow Heat Exchanger Geometries”, J. Heat Transfer 111(2), 294-299 (May 01, 1989), asme.org.
5 Indian Standard (IS: 4503-1967): Specification for Shell and Tube Type Heat Exchangers, BIS 2007, New Delhi.
6 Wolverine Tube Heat Transfer Data Book.
7 Dutta B.K. “Heat Transfer-Principles and Applications”, PHI Pvt. Ltd., New Delhi, 1st ed. 2006. Vindhya Vasiny Prasad Dubey, Raj RajatVerma, PiyushShankerVerma, A. K. Srivastava, “Steady State Thermal.
8 Analysis of Shell and Tube Type Heat Exchanger To Demonstrate The Heat Transfer Capabilities Of Various Thermal Materials Using Ansys”, Global Journals Inc., GJRE Volume 14, Issue 4, ISSN- 09755861.