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Two waste heat recovery systems of barbershops were presented to increase its heat utilization efficiency. One was the waste heat recovery system with water-to-water heat exchanger (WHR-HE). The other is the waste heat recovery system with both water-to-water heat exchanger and heat pump (WHR-HE-HP). The two waste heat recovery systems were analyzed by both economics and thermodynamics principles. Compared to conventional heat utilization systems of barbershops, the WHR-HE decreases annual energy consumption by 54.2%, and the WHR-HE-HP decreases annual energy consumption by 87.5%. The gain investment recovery periods of WHR-HE and WHR-HE-HP are below half one year. Compared to the WHR-HE, the WHR-HE-HP is with larger energy-saving potential, lower running cost, larger first cost and larger gain investment recovery period. The critical value of energy-saving financial subsidy is 0.778 ¥/W for the WHR-HE-HP. The WHR-HE-HP is very suited to the large and medium-sized barbershops, especially in the cold climate zone.

The thermal performance Rov of Flat-Plate Closed-Loop Pulsating Heat Pipe(FCLPHP) are effected by several elements such as the heat load Q, the tilt angle θ and the filling ratio F, they are interacted each other. In order to predict the effect of Q and θ on the thermal performance at locations Q and θ other than the experimental data conditions, and to study the relationship among the Rov, Q and θ in the range of the experimental data, we need a fitted regression model to estimate the function relationship that describes the data. The postulated depends on the range of the regression variables encountered in the data. In this paper, a simple model was developed. Since the coefficients in the model have been estimated from the experimental data, studies were carried out on an experimental set-up. FC72 was employed as working fluid. Method of least squares was used for building the model. By using the model, effects of the heat load and the tilt angle on the thermal performance of FCLPHP were discussed. It was found that the tilt angle had minimum value in a certain heat load in the experimental range (θ=30° -70°), and it increases with the increase of heat load. A sensitivity analysis was done with the model.

Pulsating heat pipes are high efficiency heat transfer components having a great potential application in the field of electronic cooling and space applications. In this investigation, an experiment was conducted to study the influence of working fluid thermophysical properties on the thermal performance of flat-plate closed loop pulsating heat pipes (FCLPHP). The analysis of the forces acting on the liquid-vapor mixture shows that the surface tension, viscosity and latent heat of vaporization have important impact on the thermal performance of FCLPHP. The overall thermal resistance decreases with the decrease in surface tension, viscosity and latent heat of vaporization, leading to the heat transfer improvement of FCLPHP. An experimental correlation was developed to describe the relationship among the relative overall thermal resistance and the relative thermophysical properties. With the correlation, a sensitivity analysis was made. The results show that latent heat of vaporization is the prior factor to the all others to impact the thermal performance of FCLPHP.