Tube Side Flow Rate Distribution in a Horizontal Multitube Heat Exchanger. 2nd Report. Control of Flow into Branch Tubes.

Different overlap configurations of discontinuous helical baffles affect the flow pattern of the shell-side fluid directly, and thus there is a significant impact on the flow and heat transfer characteristics of the shell-side fluid. In the present paper, experiments were carried out to study the impact of baffle overlap proportion on the shell-side flow and heat transfer performance of the shell-and-tube heat exchanger with helical baffles (STHEHB). Two different shell-side friction factors, the friction factor per helical pitch (fs,1B) and the friction factor per tube length (fs,1m), were defined based on different reference lengths. The results showed that, since the baffle overlap proportion leads to different helical pitch as well as flow fields in shell side, opposite conclusions are obtained by choosing different reference length. Based on the same Reynolds number, the shell-side Nusselt number of the STHEHB with 10% baffle overlap is higher than that with 50% baffle overlap. The reason is that the larger baffle overlap proportion produces more serious leak flows and weakens the heat transfer in shell side. The comparison of heat transfer coefficient per unit pressure drop versus shell-side flow rate showed that the STHEHB with smaller baffle overlap proportion has better comprehensive heat transfer performance, but the difference between the two decreases gradually with the increase of the flow rate.

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Experimental investigation on heat transfer and pressure drop of conical coil heat exchanger

Thermal Science ◽

10.2298/tsci140802137p ◽

2016 ◽

Vol 20 (6) ◽

pp. 2087-2099 ◽

Cited By ~ 3

Author(s):

Pramod Purandare ◽

Mandar Lele ◽

Raj Gupta

Keyword(s):

Heat Transfer ◽

Nusselt Number ◽

Heat Exchanger ◽

Pressure Drop ◽

Flow Rate ◽

Cone Angle ◽

Tube Diameter ◽

Flow Rates ◽

Side Flow ◽

Coil Heat

The heat transfer and pressure drop analysis of conical coil heat exchanger with various tube diameters, fluid flow rates, and cone angles is presented in this paper. Fifteen coils of cone angles 180? (horizontal spiral), 135?, 90?, 45?, and 0? (vertical helical) are fabricated and analysed with, same average coil diameter, and tube length, with three different tube diameters. The experimentation is carried out with hot and cold water of flow rate 10 to 100 L per hour (Reynolds range 500 to 5000), and 30 to 90 L per hour, respectively. The temperatures and pressure drop across the heat exchanger are recorded at different mass flow rates of cold and hot fluid. The various parameters: heat transfer coefficient, Nusselt number, effectiveness, and friction factor, are estimated using the temperature, mass flow rate, and pressure drop across the heat exchanger. The analysis indicates that, Nusselt number and friction factor are function of flow rate, tube diameter, cone angle, and curvature ratio. Increase in tube side flow rate increases Nusselt number, whereas it reduces with increase in shell side flow rate. Increase in cone angle and tube diameter, reduces Nusselt number. The effects of cone angle, tube diameter, and fluid flow rates on heat transfer and pressure drop characteristics are detailed in this paper. The empirical correlations are proposed to bring out the physics of the thermal aspects of the conical coil heat exchangers.

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Response of Single-Pass Heat Exchangers to Disturbances in Flow Rate

Journal of Mechanical Engineering Science ◽

10.1243/jmes_jour_1965_007_048_02 ◽

1965 ◽

Vol 7 (3) ◽

pp. 318-327 ◽

Cited By ~ 5

Author(s):

I. C. Finlay ◽

N. Dalgleish

Keyword(s):

Heat Exchanger ◽

Flow Rate ◽

Transfer Functions ◽

Mean Value ◽

Tube Length ◽

Outlet Temperature ◽

Tube Heat Exchanger ◽

Single Pass ◽

Lumped Parameter ◽

Side Flow

From distributed and lumped parameter models of a single-pass, shell and tube heat exchanger, transfer functions are derived relating the outlet-temperature responses to tube-side flow-rate disturbances. Predicted and measured data are compared over a range of mass flows and of amplitudes of the disturbing, tube-side flow signal. Good agreement is shown between measured responses and responses predicted by sectionally lumped and distributed parameter models for amplitudes of up to ±30 per cent of the mean value. The effects on the dynamic response of a distributed single-pass heat exchanger, of altering such characteristics as tube length, tube and shell-wall capacitance and mass flow rates, are illustrated graphically, and discussed.

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The flow rate distribution in branch passages of heat exchanger for automobile

Journal of the Visualization Society of Japan ◽

10.3154/jvs.15.supplement1_89 ◽

1995 ◽

Vol 15 (Supplement1) ◽

pp. 89-92

Author(s):

Mitsunobu Akiyama ◽

Hitoshi Sugiyama ◽

Shirou Ikuta

Keyword(s):

Heat Exchanger ◽

Flow Rate ◽

Rate Distribution

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