# Engine

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Thermal Engineering Laboratory
Heat Exchangers

Introduction

The purpose of this report is evaluate the performance of the Heat Exchangers. In this experiment we studied the operating principle and performance for two types, tube and shell and plate Heat Exchangers. A heat exchanger is a device built for efficient heat transfer from one medium to another, transfer heat from a fluidflowing on one side of a barrier to another fluid (or fluids) flowing on the other side of the barrier. Heat exchangers are normally used only for the transfer and useful elimination or recovery of heat without an accompanying phase change. The fluids on either side of the barrier are usually liquids, but they may also be gases such as steam, air, or hydrocarbon vapors; or they may be liquid metalssuch as sodium or mercury.

The present experiment intends to study the operating principle and performance of heat exchanger, especially the shell and tube heat exchanger, for both parallel and counter flow. The principal purpose of the present experiment is to understand the principles of heat transfer between two fluid streams separated by a solid wall and how geometry affects itsperformance. Apply both, the Log Mean Temperature Difference (LMTD) and the Number of Transfer Units (NTU) methods. To determine the overall efficiency, the overall effectiveness, the LMTD and its correction factor, the NTU, and the total heat loss in the system. On this report you will see the required mathematical analysis for a shell and tube heat exchanger.

DATA AND RESULTS (See final comments andthe end of the each Tasks)

Task No 1: Heat transfer thru a wall
|Sample |Hot Water|
|Number | |
| |Flowrate |
| |Fhot |
| |(l/min) |
|Tln |25.33 |
|  |  |
|A |0.018 |
|  |  |
|U |1.874 |

HT33(Shell and Tube H.E)
|ht33 |  |
|A|0.0181 |
|  |  |
|Tln |27.771 |
|  |  |
|U |1.4473 |

| || |

HT32(Plate H.E.)

|ht32 |  |
|A |0.0181 |
|  |  |
|Tln |17.33 |
|  |  |
|U |5.23536055 |
| | ||
| | |
|A |0.0181 |
|  |  |
|Tln |30.707 |
|  |  |
|U |1.3503 |

|HT31 |  |
|Tln |26.36116763 |
|  |  |
|A |0.018064158 |
|  |  |
|U |1.798958475 ||HT32 |  |
|A |0.02 |
|  |  |
|Tln |13.72 |
|  |  |
|U |5.75 |

Notice the U(Overall Heat Transfer cohefficient is high on HT32 Plate HE, due to a efficiency, area over the other types, and mentioned on theoretical background.

Task No 5: Effectof mass flow on heat exchanger performance
Shell and Tube Heat Exchanger Data Obtained at Different Hot and Cold Flowrates for Countercurrent Flow @ 40,50,60,70°C
Q(Kw)=heat transfer
U(W/m^2*K)=Overall coefficient