The plasma polymerization method and dynamic ion-beam mixed implantation method were employed to coat ultra-thin polymer films on copper plates. Experiments indicated that steady dropwise condensation of steam at atmospheric pressure occurred. The condensation heat transfer coefficients increased by approximately 3 and 5-7 times for the polytrimethylvinylsilane film and polytetrafluoroethylene film respectively, compared with the value for film condensation under the same experimental conditions. The temperatures on the condensing surface and inside the test block were found to be rapidly and randomly fluctuated. The properties of the coated films and advantages of the methods used in this investigation were discussed briefly.

The present paper reports an experimental investigation of film condensation in a vertical, internally finned tube with a wire insert. The finned tube and wire insert were chosen as the best performing from a series of tubes and inserts tested separately in previous investigations. Compared with previous results for the finned tube, it was found that only for ∆T>10K did the addition of the insert somewhat improve the heat transfer performance. However, the pressure drop for the finned tube with insert was increased. Empirical correlations for friction factors for the three tube configurations are proposed based on the present data.

Six surfaces were propared with different surface division patterns for the experimental investigation of steam condensation heat transfer charactc rlstics for dropwise and filmwise coexisting (DFC) condensation surfaces under atmosplmric pressure Dropwise condensation (DWC) was promoted with an uhrathin poly tetrafluorethvene (PiFE) fiim, which was prepared by the dynamic ion-beam mixed implantation (DIMI) method. The results showed that the eondensatiou phenomena at the intersection between the dropwise and filmwise condensation regions wer (quite different ior different relative positions of the dropwise and filmwise condensation regions. The experimental results revealed that the condensation heat transfer characteristics were highly influenced by the surface division number and the relative area ratio of the dropwise and filmwise eondensation regions. The impact of these findings on heat transfer enhancement mechanism for condensation heat transter is discussed in detail.

Film condensation on a vertical porous coated plate is investigated numerically for a porous/fluid composite system based on the dispersion effect in the porous coating. The mathematical model improves the conventional matching conditions by considering the stress force at the porous coating interface. The numerical results show the ef-fects of the porous coating thickness, the effective thermal conductivity and the permeability on condensate film thickness and local Nusselt number. The predicted average Nusselt number has similar tendencies to experimental results reported in iterature, such that using a thin porous coating would be a viable alternative for enhancing the condensation heat transfer.

This paper reports the test results of the first industrial-scale absorption heat transformer (AHT) equipment in China, to recover the waste heat released from mixture of steam and organic vapor at 98 C in coacervation section, synthetic rubber plant of Yanshan Petrochemical Corporation, Beijing, China. The recovered heat is used to heat hot water from 95 to 110 C, feeding back to the coagulator as the supplementary heating source. The AHT system is operating with H2O/LiBr solution with heat flow of 5000kW. The coefficient of performance (COP), the thermal efficiency and the temperature lift of the AHT system are presented. The heat transfer characteristics of the AHT components, i.e. absorber, generator, evaporator, condenser and the liquid-liquid solution heat exchanger, are also illustrated by comparison of experimental data and the model calculated results. The results show that the mean COP is 0.47, the gross temperature lift of 25 C can be realized and the payback period is 2 years.