What is the most common size of tube in heat exchanger?

Tubes may range in diameter from 12.7 mm (0.5 in) to 50.8 mm (2 in), but 19.05 mm (0.75 in) and 25.4 mm (1 in) are the most common sizes.

What is equivalent diameter in heat exchanger?

The equivalent diameter is given by deq = 4S/P, where S is the cross section and P the perimeter of the flow, L is the path length and ξ is a friction factor expressed as a function of Reynolds number and device geometry. Heat transfer and pressure drop calculations are interrelated.

Why a large number of tubes is used in heat exchangers?

The fluids can be either liquids or gases on either the shell or the tube side. In order to transfer heat efficiently, a large heat transfer area should be used, leading to the use of many tubes. In this way, waste heat can be put to use. This is an efficient way to conserve energy.

What is the difference between double pipe and shell and tube heat exchanger?

Double pipe heat exchanger consists of two concentric pipes of different diameters. One pipe is for hot fluid and another is for cold fluid. Shell and tube heat exchanger consists of a shell in which large number of parallel tubes are present. One fluid hot or cold flow in shell and other hot or cold flow in the tubes.

How do you size a heat exchanger?

ΔTm =

1. ΔTm =
2. = 94.9 °F. 0.10536.
3. The preliminary area estimate of the heat exchanger can now be calculated as: A = Q / (U x ΔTm) =
4. A = 2, 035, 000 Btu/hr.
5. = 178.7 ft² (120 Btu/h.ft².°F).(94.9°F)
6. The required mass flow rate of water can be calculated from Q = m.Cp. ΔTm: Rearranging:
7. m = Q…… = Cp x ΔTm.
8. m = (2,035,000 Btu/hr)

How does number of tubes affect heat exchanger?

For example, in a single pass heat exchanger, more tubes means lower velocities and lower pressure drop. If this was a multipass heat exchanger, more tubes could mean more passes and higher pressure.

What is equivalent diameter in pipe flow?

The equivalent diameter is the diameter of a circular duct or pipe that for equal flow gives the same pressure loss or resistance as an equivalent rectangular duct or pipe.

What is meant by equivalent pipe?

Equivalent pipe : The pipe of uniform diameter having loss of head and discharge equal to the loss of head and discharge of a compound pipe, consisting of several pipe of different length and diameters.

How many tubes can a heat exchanger have?

In Power plant 500-1000 MW or more turbine hot well surface condenser are available more than 10,000 Number of tubes. waste heat boiler in power plant gas turbine are shell & tube type heat exchanger are also larger size and having 5000-12000 number of tubes.

How many tubes are there in shell and tube heat exchanger?

The three types of Shell and tube heat exchangers as Follows : Fixed Tubesheet – this heat exchanger type has straight tubes through the shell and are fixed at both ends. U-Tube – as the name describes, the tube bundle in this heat exchanger is U shaped.

Where would you use shell and tube double pipe heat exchangers?

When to use double pipe heat exchanger and shell and tube heat exchanger? Double pipe heat exchangers are used when the heat transfer area is small say up to 14 m2. If we connect them in series to increase the heat transfer area it will require much space as well the pressure drop will be higher due to more fittings.

Why shell and tube heat exchanger is used?

Shell and tube heat exchangers make it possible to pump materials as soon as possible, and they transfer temperatures efficiently so you can ensure the materials are at the necessary temperature without expending extra energy to do so.

How many tubes are in a tube heat exchanger?

Inside, they can contain one tube or a tube bundle (similar to shell and tube heat exchangers ), but the bundle must be < 30 tubes and the outer pipe must be < 200mm in diameter, or the heat exchanger qualifies as another design (See our article on shell and tube heat exchangers for more information).

Are double pipe heat exchangers more efficient than shell and tube?

If the budget and space exists for a shell and tube exchanger, then a double pipe design is often a less efficient method of heat transfer The double pipe heat exchanger, as seen above, is perhaps the simplest heat exchanger in industry.

How do I determine the side heat transfer coefficient of Tubetube?

Tube side heat transfer coefficients are easy to determine, since the Seider-Tate equation (or equivalent) applies. The most common slipup made at this stage is to incorrectly divide the stream flow among the tubes. Be sure to adjust all flowrates and velocities for the number of tubes AND the number of tube passes.

Why is counterflow used in a double pipe exchanger?

True counterflow is achieved in double pipe exchangers because of the concentric tube (s), and designers take advantage of this to increase the system’s heat transfer coefficient. They can also be used in parallel flow where both fluids move in the same direction, but counterflow is often the most thermally efficient regime.