Thermal behavior of spiral fin-and-tube heat exchanger having fly ash deposit

Journal Article · Wed Aug 15 00:00:00 EDT 2007 · Experimental Thermal and Fluid Science

DOI:https://doi.org/10.1016/J.EXPTHERMFLUSCI.2006.11.007· OSTI ID:20919394

Nuntaphan, Atipoang ^[1]; Kiatsiriroat, Tanongkiat ^[2]

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1. Thermal Technology Research Laboratory, Mae Moh Training Center, Electricity Generating Authority of Thailand, Mae Moh, Lampang 52220 (Thailand)
2. Department of Mechanical Engineering, Chiang Mai University, Chiang Mai 50200 (Thailand)

This research investigates the effect of fly-ash deposit on thermal performance of a cross-flow heat exchanger having a set of spiral finned-tubes as a heat transfer surface. A stream of warm air having high content of fly-ash is exchanging heat with a cool water stream in the tubes. In this study, the temperature of the heat exchanger surface is lower than the dew point temperature of air, thus there is condensation of moisture in the air stream on the heat exchanger surface. The affecting parameters such as the fin spacing, the air mass flow rate, the fly-ash mass flow rate and the inlet temperature of warm air are varied while the volume flow rate and the inlet temperature of the cold water stream are kept constant at 10 l/min and 5 C, respectively. From the experiment, it is found that as the testing period is shorter than 8 h the thermal resistance due to the fouling increases with time. Moreover, the deposit of fly-ash on the heat transfer surface is directly proportional to the dust-air ratio and the amount of condensate on heat exchange surface. However, the deposit of fly-ash is inversely proportional to the fin spacing. The empirical model for evaluating the thermal resistance is also developed in this work and the simulated results agree well with those of the measured data. (author)

• OSTI ID: 20919394
• Journal Information: Experimental Thermal and Fluid Science, Vol. 31, Issue 8; Other Information: Elsevier Ltd. All rights reserved; ISSN 0894-1777
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
FLY ASH
AIR
HEAT EXCHANGERS
HEAT TRANSFER
DEPOSITS
DEW POINT
SURFACES
TUBES
FINS
FLOW RATE
WATER
FOULING
HEAT
MASS
CONDENSATES
DUSTS
MOISTURE
PERFORMANCE
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K
TIME DEPENDENCE
WASTE HEAT UTILIZATION