DESIGN AND OPERATION OF A SHELL AND TUBE HEAT EXCHANGER (SINGLE PHASE FLOW)
CHAPTER ONE
- INTRODUCTION
Shell and tube heat exchangers are used extensively throughout the process industry and as such a basic understanding of their design, construction and performance is important to the practicingengineer.
The objective of this paper is to provide a concise review of the key issues involved in their thermal design without having to refer to the extensive literature available on this topic.
The optimum thermal design of a shell and tube heat exchanger involves the consideration of many interacting design parameters which can be summarized as follows:
Process
- Process fluid assignments to shell side or tubeside.
- Selection of stream temperaturespecifications.
- Setting shell side and tube side pressure drop designlimits.
- Setting shell side and tube side velocitylimits.
- Selection of heat transfer models and fouling coefficients for shell side and tubeside.
Mechanical
- Selection of heat exchanger TEMA layout and number ofpasses.
- Specification of tube parameters – size, layout, pitch andmaterial.
- Setting upper and lower design limits on tubelength.
- Specification of shell side parameters materials, baffle cut, baffle spacing andclearances.
- Setting upper and lower design limits on shell diameter, baffle cut and bafflespacing.
There are several software design and rating packages available, including A spen BJAC, HTFS and CC-THERM, which enable the designer to study the effects of the many interacting design parameters and achieve an optimum thermal design. These packages are supported by extensive component physical property databasesand
thermodynamic models.
It must be stressed that software convergence and optimisation routines will not necessarily achieve a practical and economic design without the designer forcing parameters in an intuitive way. It is recommended that the design be checked by running the model in the rating mode..
Detailed mechanical design and construction involving tube sheet layouts, thicknesses, clearances, tube supports and thermal expansion are not considered but the thermal design must be consistent with the practicalrequirements.
1.2. STATEMENT OF THE PROBLEM
Products of crude oil are used in different application areas especially in industries (textile industry) but from their ordinary properties the amount of energy transferred becomes un sufficient to the required process and also the final out put product gained from the process is also qualityless.
1.3. OBJECTIVE
1.3.1. General Objective
The general objective of this paper is to know and understand design of shell and tube heat exchanger. Hence design of shell and tube heat exchanger for single phase flow manually and using C++ programing is the general objective.
1.3.2. SpecificObjective
Based on the general objective the specific objective is considering specific activities that build up to the general objective. Due to this the specific objective of this paper is to know and practice the kern method (log min temperature difference method LMTD and effectiveness method NTU) and to develop software programing capabilities (Borland C++).
DESIGN AND OPERATION OF A SHELL AND TUBE HEAT EXCHANGER (SINGLE PHASE FLOW)