abstract: in this study, al 2 o 3 /eg and tio 2 /eg nanofluids as coolants have been used in the double-tube heat exchanger. the hot solvent inlet heat exchanger must be cooled down with a specified amount. we can use nanofluids as coolants in the heat exchanger for optimization of the heat transfer area. therefore, the efficacy of nanofluids as coolants is verified. furthermore, flow rate of c...

the performance of a γ-al 2 o 3 /n-decane nanofluid shell-and-tube heat exchanger in a biomass heating plant is analyzed to specify the optimum condition based on the maximum heat transfer rate and performance index for wide range of nanoparticle volume fraction (0–7%). compared with pure          n-decane, the obtained results in this research show that by using γ-al 2 o 3 /n-decane nanofluid ...

longitudinal heat conduction is an important parameter in the cryogenic field, especially in cryogenic heat exchangers. in the present work, the parasitic effect of tube wall longitudinal heat conduction on temperature measurement has been studied in cryogenic laminar hydrogen flow. the effects of various parameters such as wall cold end temperature, wall thermal conductivity, gas volumetric fl...

sometimes the need for non-circular ducts arises in many heat transfer applications because of lower pressure drop of non-circular cross section such as square duct compared to circular tube, particularly in compact heat. but square cross section has poor heat transfer performance and it is expected that using a nanofluid as a new heat transfer media may improve the heat transfer performance of...

if an air flow is injected into a liquid fluid, many ambulant air bubbles are formed inside the fluid. air bubbles move inside the liquid fluid because of the buoyancy force, and the mobility of these air bubbles makes sizable commixture and turbulence inside the fluid. this mechanism was employed to enhance the heat transfer rate of a horizontal double pipe heat exchanger in this paper. howeve...

the use of solar collectors in combination with heat pipes is rapidly growing in recent years.heat pipes, as heat transfer components, have undeniable advantages in comparison with other alternatives. the most important advantage is their high rate of heat transfer at minor temperature differences. although there have been numerous studies on the heat analysis or first thermodynamic analysis of...

background: pastry occupation is one of occupations to exposure with heat and significant number of workers works at it. this study is aimed to heat stress and heat strain score index assessment in the pastry workers of isfahan.   methods: this cross sectional and descriptive study was conducted on 360 pastry workers between 10 and 14 hours in the summer of 2012. wbgt index was used for determi...

background: heat stress is one of the agents in the work environment that can create numerous problems for workers. the objective of this research is to study heat stress control in the foundry platform of a steel plant in tehran. methods: in this experimental study, controlling plans were demonstrated for the work conditions improvement in one of steel plant's foundry platforms. for controllin...

abstract background: heat is one of the most important of harmful agents in many working environments such as bakeries that can cause prevalence of diseases related to heat and falling of efficiency. aim of this study was exposure evaluation of isfahan bakers to heat stresses in their working environment through evaluation of relationship among wet bulb globe temperature index (wbgt) , oral tem...