An experimental study of heat transfer characteristics with and without insert was found using water –water system on 1-2 pass shell and tube heat exchanger. Experimental results such as exchanger effectiveness, overall heat transfer coefficient were calculated using with and without insert. There is improvement in overall heat coefficient, efficiency in using twisted tape. In all the process i...

A full scale snow melting system with heat pipe technology is built in this work, which avoids the negative effects on concrete structure and environment caused by traditional deicing chemicals. The snow melting, ice-freezing performance and temperature distribution characteristics of heat pipe concrete runway were discussed by the outdoor experiments. The results show that the temperature of t...

Heat pipe is a device that transports heat with minimal temperature drop using the latent heat of fluid in a closed container. In vertical type named as thermosyphon (Wickless), capillary action is replaced by the gravitational force, this condenser is placed above evaporator. In this paper, to investigate the effect of inlet air temperature and the air mass flow rate was studied. The temperatu...

Total thermal resistance of ground heat exchanger (GHE) is comprised of that of the soil and inside the borehole. The thermal resistance of soil can be calculated using the linear source theory and cylindrical source theory, while that inside the borehole is more complicated due to the integrated resistance of fluid convection, and the conduction through pipe and grout. Present study evaluates ...

The deterioration of the performance of a cross flow heat exchanger with condensation due to the longitudinal conduction was investigated. For a relatively small change of wall temperature along the flow directions which was shown to be common in many applications, the energy equations were solved numerically. An iterative method was used to solve the resulting equations of the finite differenc...

the present study investigated the effect of distilled-water/ silver nanofluid on heat transfer in a closed cooling system of one of the electrical energy generation units at isfahan power plant. the difference between this study and previous researches refers to silver properties which have a high thermal conductivity and is non-toxic, hydrophilic and eco-friendly. distilled water/ silver nano...

This work presents an experimental investigation of the thermal performance of a flatplate heat pipe during startup and shutdown operations. Using the analytical model developed in a previously study, analytical and experimental results on the effect of input power and cooling heat transfer coefficient on the thermal performance of the heat pipe are presented and discussed. The results indicate...

joule-thomson cooling systems are used in refrigeration processes such as cryogenic gas liquefaction. although extensive studies have been carried out by researchers, most of them include cryogenic heat exchangers and their associated fields. in the current study, an attempt was made to indicate the effect of using inappropriate operational conditions in a cryogenic joule-thomson cooling system...

Performance was evaluated for a passive solar space heating system utilizing heat pipes to transfer heat through an insulated wall from an absorber outside the building to a storage tank inside the building. The one-directional, thermal diode heat transfer effect of heat pipes make them ideal for passive solar applications. Gains by the heat pipe are not lost during cloud cover or periods of lo...

The ceramics industry is the second largest energy consuming sector in Europe. main used heat generated through burners using natural gas. area can be identified three stages, drying stage and firing stage, cooling stage. represents about 75% of total cost. roller hearth kiln technology considered to most cost-effective solution for ceramic tile manufacturing. separated into two sections, gener...