5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics 2007http://hdl.handle.net/2263/396042024-03-28T17:05:31Z2024-03-28T17:05:31ZDesign, development and evaluation of a solar powered absorption cooling system for South African conditionsNwamba, K.J.Meyer, C.F.Louwrens, D.http://hdl.handle.net/2263/499322022-04-08T22:47:55Z2007-01-01T00:00:00ZDesign, development and evaluation of a solar powered absorption cooling system for South African conditions
Nwamba, K.J.; Meyer, C.F.; Louwrens, D.
Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.; Solar assisted adsorption cooling is one current research area where scientists study the development of new and safe cooling technologies; so that the conventional vapour
compression refrigeration; with its many disadvantages; might
be discarded. It has been investigated during the last decade,
with some success. One problem facing researchers is to do
detail comparisons for the two systems on the cost
effectiveness, so that the best option is identified.
This study presents an experimental analysis of a solar
assisted adsorption fridge, and compares its cost effectiveness
with the conventional vapour compression system, so that a
cost effective fridge can be found for South African
conditions.
The machine is operated by a solar powered flat plate, with
collectors containing the adsorbent. The adsorbent – adsorbate
pair chosen for this study is water and silica gel. The cooling
machine was designed, developed and tested. Preliminary
results show that chilled water at temperatures of 6 0C and
12 0C is produced. The cost effective comparisons shows that
a solar adsorption cooling machine represent an energy saving
machine with a good economic competitiveness.
2007-01-01T00:00:00ZHeater surface coating effect on fluidized bed heat transfer coefficientPatil, A.P.Bosco, GonmeiKeishing, JoelNarry, BankerlangKharraswai, Joppharhttp://hdl.handle.net/2263/499302022-04-08T22:47:51Z2007-01-01T00:00:00ZHeater surface coating effect on fluidized bed heat transfer coefficient
Patil, A.P.; Bosco, Gonmei; Keishing, Joel; Narry, Bankerlang; Kharraswai, Jopphar
Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.; The effect of different coatings painted on the heat
transfer surface of the horizontal heater in a vertical fluidized
bed heat transfer unit is studied. Polyurethane and
polyurethane based zinc coatings are applied on the horizontal
heat transfer surfaces and their effects on the heat transfer
coefficient are investigated for different heater heights,
different heater heat inputs and for different superficial
velocities. It is found that the application of polyurethane
coatings has decreased the heat transfer coefficient as
compared to the heat transfer coefficient obtained with the
bare uncoated heater. It is also found that by applying the
polyurethane based zinc coatings the heat transfer coefficient
has increased as compared to that obtained with the
polyurethane coating. Procedure and the results of the
experiments done to study this fluidized bed heat transfer
analysis are presented in this paper.
2007-01-01T00:00:00ZPool boiling of deionised water over polyurethane coated surfacesPatil, A.P.Ezung, SorenthungChalai, KholiIbomcha, Likmabamhttp://hdl.handle.net/2263/498912022-04-08T22:47:51Z2007-01-01T00:00:00ZPool boiling of deionised water over polyurethane coated surfaces
Patil, A.P.; Ezung, Sorenthung; Chalai, Kholi; Ibomcha, Likmabam
Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.; Preliminary investigations are done to cater the possibility of
the use of the polyurethane coating for the pool boiling heat
transfer augmentation. Experiments have been done on the
bare stainless steel heater and stainless steel heaters coated
with polyurethane coatings of different thicknesses, by boiling
deionised water at constant atmospheric pressure. Contact
angle formed by the deionised water over the test specimen
are experimentally measured and from these values the solidliquid
surface energy values have been calculated. It has been
found that the polyurethane coating has increased the solidliquid
surface energy and the heat transfer. Recommendations
for the future inspections with relevance to finding an ideal
heat transfer enhancer coating are putforth.
2007-01-01T00:00:00ZNumerical prediction of developing flow in gas pipelinesNouri-Borujerdi, A.Ziaei-Rad, M.http://hdl.handle.net/2263/457612022-04-08T22:47:36Z2007-01-01T00:00:00ZNumerical prediction of developing flow in gas pipelines
Nouri-Borujerdi, A.; Ziaei-Rad, M.
Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.; In this paper the numerical modeling of the dynamic
behavior of compressible gas flow is investigated in pipelines.
The numerical simulation is performed by solving the coupled
conservation form of the governing equations for twodimensional,
laminar, viscous, supersonic flow in developing
region under different thermal boundary conditions. The
numerical procedure is a finite-volume based finite-element
method applied on unstructured grids. The convection terms are
discretized by well-defined Roe Method and diffusion terms by
a Galerkin finite element formulation. The temporal terms are
evaluated based on an explicit fourth order Runge-Kutta
scheme.
The results indicate that heating the gas flow leads to an
increase in pressure loss. In the other words, cooling the gas
flow leads to decrease the pressure drop or power consumption
of booster pressure station. Furthermore, change in the gas
viscosity has considerable effects on the flow quantities such as
pressure loss and friction factor.
2007-01-01T00:00:00Z