Ask Question, Ask an Expert


Ask Civil Engineering Expert

problem 1: A concentric tube heat exchanger is comprised of a thin wall inner tube of 25.4 mm diameter and an outer tube of 47 mm diameter. The heat exchanger is used for cooling lubricating oil. The exchanger operates in counterflow, the inner tube carrying water and the outer tube carrying the oil with an overall heat transfer coefficient of 65 W/m2K.

a) If the oil outlet temperature is 55oC, determine the total heat transfer and the water outlet temperature.
b) Determine the length required for the tube heat exchanger.

problem 2
: A concentric tube heat exchanger, counterflow arrangement was designed to heat water from 20oC to 80oC using hot oil that is supplied to the annulus at 160oC and discharged at 140oC. The thin-walled inner tube has a 20 mm diameter. The overall heat transfer coefficient if 527 W/m2 K. The designed condition requested a total heat transfer rate of 3700 W.

a) What  is the length of this heat exchanger?
b) After 3 years of operation, the heat exchanger performance is degradated by fouling on the water side, and the water outlet temperature is 57oC for the same flow rate and inlet temperatures. What are the corresponding values of the heat transfer rate, the oil outlet temperature, the overall heat transfer coefficient, and the water side fouling factor, R”f,c?

problem 3: A Shell-and-tube Heat Exchanger (1 shell pass, 2 tube passes) is to be used to condensate 3.21 kg/s of saturated steam at 350K. Condensation occurs on the outer tube surfaces, and the corresponding convection coefficient is 10,215 W/m2K. The temperature of the cooling water entering the tubes is 15oC. Thin-walled tubes of 20mm diameter are specified, and the mean velocity of water flow through the tubes is to be maintained at 0.45 m/s.

a) What  is the minimum number of tubes that should be used?
b) What  is the corresponding tube length per pass?
c) To reduced the size of the heat exchanger, it is proposed to increase the water side convection coefficient by inserting a wire mesh in the tubes. If the mesh increases the convection coefficient by 2, what is the required tube length per pass?

problem 4: A customer requested the design of a Heat Exchanger and provided the following information to the Engineering Department. In his factory, as part of the process upgrade, there is a need to heat 97.2 m3/hr of cold water from 32oC to 60oC. The heat is available from 100.8 m3/hr of hot water at 90oC. The customer does not know of any other information that could lead to a final configuration of heat exchanger type. In this initial stage, he requires a preliminary design that can be evaluated to determine what additional requirements should be considered.

In a meeting conducted at the Engineering Department, it was decided to:

a) Design the Heat Exchanger with the information provided. In this stage, all assumptions must be listed and describeed for customer evaluation and review.

b) Prepare Heat Exchanger drawings of the proposed solution/s.

c) At the same time, the design must be evaluated to identify features and configurations that could be discussed with the customer with the aim of developing more complete specifications.

d) Cost analysis in not required.

Civil Engineering, Engineering

  • Category:- Civil Engineering
  • Reference No.:- M91949

Have any Question? 

Related Questions in Civil Engineering

Represent each of the force systems with a force-couple

Represent each of the force systems with a force-couple system having the force act at point A. Which systems are equivalent to each other?

The four forces shown act on the rollers of an in-line

The four forces shown act on the rollers of an in-line skate. Determine the equivalent force-couple system, with the force acting at O (the ankle joint of the skater).

Repeat problem p109 but use the numerals 1 2 and 4 instead

Repeat Problem P10.9, but use the numerals "1", "2" and "4", instead of the letters "T", "G" and "F". Test the trained network on each reference pattern and on noisy patterns. Discuss the sensitivity of the network. (Use ...

Determine the force-couple system with the force acting at

Determine the force-couple system, with the force acting at point O, that is equivalent to the force and couple acting on the arm CD of the industrial robot. Note that the arm ABCD lies in a vertical plane that is inclin ...

Repeat the work of widrow and hoff on a pattern recognition

Repeat the work of Widrow and Hoff on a pattern recognition problem from their classic 1960 paper [WiHo60]. They wanted to design a recognition system that would classify the six patterns shown in Figure P10.11. These pa ...

An n-bit updown counter is a sequential circuit with a

An N-bit up/down counter is a sequential circuit with a clock input and an up/down control input. Wen control is 1, the circuit counts up, modulo 2N, on each rising edge of the clock. In other words, the present-state ou ...

Is it possible to assign valid logic levels and noise

Is it possible to assign valid logic levels and noise margin boundaries so that a device with the following transfer characteristic would serve as an inverter? Briefly explain your reasoning

Convert the classification problem defined below into an

Convert the classification problem defined below into an equivalent problem definition consisting of inequalities constraining weight and bias values.

1 what decimal integer does the -bit 2s complement number

1. What decimal integer does the $-bit 2's complement number 11 l10101 represent? 2. A positive number is added to a negative number using 2's complement arithmetic. The result has a 1 in the sign bit. Does this indicate ...

The moment of the force f about the x-axis is 1080 n middot

The moment of the force F about the x-axis is 1080 N · m. Determine the moment of F about the axis AB.

  • 4,153,160 Questions Asked
  • 13,132 Experts
  • 2,558,936 Questions Answered

Ask Experts for help!!

Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

Ask Now Help with Problems, Get a Best Answer

WalMart Identification of theory and critical discussion

Drawing on the prescribed text and/or relevant academic literature, produce a paper which discusses the nature of group

Section onea in an atwood machine suppose two objects of

SECTION ONE (a) In an Atwood Machine, suppose two objects of unequal mass are hung vertically over a frictionless

Part 1you work in hr for a company that operates a factory

Part 1: You work in HR for a company that operates a factory manufacturing fiberglass. There are several hundred empl

Details on advanced accounting paperthis paper is intended

DETAILS ON ADVANCED ACCOUNTING PAPER This paper is intended for students to apply the theoretical knowledge around ac

Create a provider database and related reports and queries

Create a provider database and related reports and queries to capture contact information for potential PC component pro