Performance Enhancement of Heat Exchanger Using Turbulators

I. INTRODUCTION

Heat exchangers are broadly utilized in chemical, power generation and oil refining industry. Shell and tube heat exchanger can transfer vast measure of heat in moderately minimal effort, useful plans. The basic variable in reducing the size and cost of a heat transfer gadget are weight drop and heat transfer coefficient. Along these lines, it respects made procedure to improve the heat transfer coefficient. The twisted tape insert as stream turbulator's have been broadly connected because of their promising execution. Numerous analysts have detailed their impact of tube insert on heat transfer improvement. The promising test for plan of heat exchanger is to reduce the pumping power while expanded heat transfer rate. In this manner it is fundamental to create hypothesis and technique about increased heat transfer in the double pipe heat exchanger to enhance the execution of heat exchanger. The presence of twisted tape brings down the hydrodynamic and thermal boundary layer thickness, prompting more noteworthy convective heat transfer. In spite of fact that pumping power may increment definitively and eventually the cost of pumping is more. In this way to accomplish a coveted heat transfer rate with least pumping power, the outline of twisted tape with legitimate geometry is important. Twisted tapes are typically embedded into the tube to produce whirl movement of liquid for more prominent heat transfer this likewise prompts enhance flow speed, thermal boundary layer, hydrodynamic boundary layer, heat transfer rate, fluid mixing. Anyway all the more pumping power is required when twisted tapes are inserted inward tube. By using heat exchangers we can transfer the heat energy of one fluid into another fluid. The heat exchangers that we encounter in our daily life‘s are the evaporators and condensers that are used in refrigerators and Air conditioners. Thermal power plants also use heat exchangers which include the condensers and Boilers. Air coolers and radiators are present in our automobiles which are also heat exchangers. Process and chemical industries also use heat exchangers. The heat exchangers are constructed according to their use and are also classified accordingly. The heat exchangers that are used most commonly mostly depend on fundamental concepts. Due to such wide variety of heat exchangers, they are classified according to the operation, heat transfer, construction and flow arrangement. The classifications are described below:

surfaces • Process of Transfer: direct and indirect contact • Heat transfer: single or two phase flow

Heat expulsion change technique says the improvement of thermo water powered execution of heat exchanger. This improvement method is categorized in generally three categories. They are as follows: a. Active method b. Passive Method

Active method: In these approaches, external power is utilized to affect the need flow statement and related important in rate of heat transfer. The main source of powering the complete system is some applied external force to the system. Passive method: These methods do not necessary have any direct input of exterior power. This method act as a passive medium to boost the system without utilizing any of the external applied force on the system. As there is no such external medium used in the method this is known to be the passive method of operation. Compound method: A compound imperative technique is the one wherever more than one of the above expressed strategy is utilized in blend by the motivation behind further progressing the rate of heat transfer.

1. Work being considered is to perform experimental examination and recreation of double pipe heat exchanger with and without twisted tape insert 2. The studies of the heat transfer performance of heat exchanger with and without insert twisted tape different geometry. Calculation of its heat transfer performance at different mass flow rate involving: a. Heat transfer coefficient for all cases. b. Nusselt number for all cases.

their specifications for the double-pipe heat exchanger. 1. Double-Pipe Heat Exchanger Inside Pipe Material:

Pass: 1

Pass: 1

Ball Valves Location: Process Valves, Tank Valve, Drain Valve, Bypass valves

Display: 31/2 digit red led 13 mm Height Accuracy: 1%F.S. Set point: 1 Potentiometric Output: INO/NC, 3A Control mode: ON/OFF Power: 230VAC 50Hz +/- 10% Size: 96 x 96 x 85 mm DIN ABS Cabinet Panel cut-out: 92 x 92mm

Input: RTD-PT100, 3 Wires Display: 3 1/2 Digit Red Led 3mm Height Size: 96 x 96 x 80 mm DIN Panel Cut-out: 92 x 92 mm Model: MPTI

Type: Emersion type Body: SS304 Capacity: 1.5KW Power: 230VAC 50Hz

Type: Centrifugal Capacity: 1/5HP Discharge: 2000LPH Foot mounting Power: 250VAC 50 Hz Size: 1‖

MOC: Acrylic Range: 250 – 0- 250mm WC

Type: RTD-PT100 3 wire Assembly: Transition type Range: 0 to 300Deg C Diameter: 6mm Length: 100mm Cable: 3mtr. Teflon/Teflon Cable

MOC: Acrylic Range: 100-1000LPH Media: Water

Power: 250VAC 50Hz

Reynolds number p = density of water v = velocity of water µ = viscosity of water = 0.5417m/s

=12052.67

For mass flow rate =0.1667kg/s Re=12052.67 f= 16/Re

=16/12052.67 =0.00132

Same as calculate for all mass flow rates

For mass flow rate =0.1667kg/s Re=12052.67

= 0.03197

Same as calculate for all mass flow rates

Graph represent between Reynolds number and nusselt number of twist tape or without twist tape inserted in heat exchanger. In below figure T.R represent the twist ratio. Above figure Plot between Nusselt number and Reynolds number for without twist tape and twisted tape with various twisted ratio inserted, concludes that nusselt number and Reynolds number. Nusselt number rise with rise in reynolds number .hence rate of convective heat transfer is more with higher reyonlds number. Further, it can reasoned that, twisted tapes with higher contort (with lesser turn proportion) give increment nusselt number for specific reynolds number. Heat transfer rate is hitter with twisted tape of lower contort proportion.

Above figure plot drawn between factor of friction and Reynolds number with varying twisted tape ratio, one can easily observe the change fraction factor with varying twisted ratio with increase in fraction, Reynolds number also increase.

exchanger with cold and hot fluids with totally different boundary conditions by incorporating twist tape inserts .It may be complete as follows: By using passive techniques that's by inserting twist tape inserts the heat transfer improvement increased by 10-15% with the price of reasonable allowable pressure drop .In this report we tend to achieved improvement of heat transfer effectively.

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Research Scholar, R.K.D.F Institute of Science & Technology, Bhopal, India