DEPAF: A Computer Model for Design and Performance Analysis of Furnaces.
DEPAF: A Computer Model for Design and Performance
Analysis of Furnaces.
(5534 K)
Chi, J.
ASME 77-HT-11;
AIChE-ASME Heat Transfer Conference. American Society
of Mechanical Engineers. August 15-17, 1977, Salt Lake
City, UT, 1977.
Keywords:
furnaces; computer models; transmission; computer
simulation; heat transfer; combustion; experiments; heat
loss; costs; heating; design applications; equations
Abstract:
The report covers the development of a computer
simulation program DEPAF (Design and Performance
Analysis of Furnaces) for residential fossil-fuel-fired
furnaces. DEPAF is based upon an analytical model
which accounts for cyclic (on-and-off) operation of
furnace burner and blower. Transmission of heat at
on-cycle
uses the theory of radiative and convective heat
transfer; transmission of heat at Off-cycle uses the
theories
of turbulent and free convective heat transfer.
Confidence in DEPAF was established by the use of
available
experimental data on a gas-fired forced-war-air furnace.
While the theory of transient heat transfer in
combustion is complex in nature, theoretical results
based upon quasi-steady-state analysis are in excellent
agreement with experiments. If the building heat loss
is known, DEPAF can be used to calculate the annual
performance and operating cost residential heating
systems with furnaces. Examples are given to illustrate
applications of DEPAF to examine quantitatively the
effect of design and operating variables on annual
performance and operating costs of residential
forced-warm-air furnaces. It was found that considerable
savings in fuel and operating costs can often be
achieved by performing certain modifications to existing
furnaces.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899