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Concentric tube heat exchanger
About: Concentric tube heat exchanger is a research topic. Over the lifetime, 5053 publications have been published within this topic receiving 81130 citations.
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TL;DR: In this article, the effects of strong solution temperature difference between inlet and outlet of solution heat exchanger on the coefficient of performance and cooling water flow rate of mixed absorption refrigeration cycle were analyzed.
Abstract: The model of solution heat exchangers of mixed absorption refrigeration cycle was developed. The effects of strong solution temperature difference between inlet and outlet of solution heat exchanger on the coefficient of performance (COP) and cooling water flow rate of mixed absorption refrigeration cycle were analyzed, at the same time, the effects of temperature difference on the unit heat exchange area of counter-flow and cross-flow solution heat exchangers were analyzed. The theoretical analysis results showed that there was an optimal value for the strong solution temperature difference, for the mixed absorption system, the optimal temperature difference was about 12°C, the corresponding COP was 11.2% higher and the cooling water flow rate was 7.8% less than that of system without heat exchanger.
01 Jan 2009
TL;DR: In this paper, a corrugated flex tube, 13 m long and 0.0254 m in diameter, is helically coiled in the heat exchanger, and temperatures and pressures are measured at both inlet and outlet of the coiled tube.
Abstract: Characteristics of heat transfer and pressure drop of a helically coiled corrugated flex tube in a heat exchanger were experimentally investigated in this study. A corrugated flex tube, 13 m long and 0.0254 m in diameter, is helically coiled in the heat exchanger. Water is selected as working fluid. Hot water flows through the tube, and cold water in the boiler is either stationary or in motion by a pump. Temperatures and pressures are measured at both inlet and outlet of the coiled tube. Flow rates are controlled by a control valve and measured by a flowmeter. The results show that friction coefficients in the present setup are considerably high (by a factor of 2.2 to 3.6) compared to the data available in the literature for a straight corrugated tube. In addition, the ratio of the friction coefficient of the present setup to that of the straight corrugated tube appears to increase as the flow rate decreases. For the case of stationary cold water in the boiler where natural convection takes place outside the tube wall, the overall heat transfer coefficient is measured to be approximately 400 W/m 2 K. The overall heat transfer coefficient increases only slightly as the flow rate inside the tube increases. When cold water in the boiler is set to a motion by a pump, on the other hand, the overall heat transfer coefficient is measured to be 800 to 1000 W/m 2 K, depending on the flow rate inside the tube. When the surface area of an imaginary smooth tube based on the outer diameter is employed in data analysis, however, the overall heat transfer coefficient is calculated to be much higher. This shows that the corrugated tube considerably enhances heat transfer rate per unit length of the tube, compared to a smooth tube.
01 Jan 2015
TL;DR: In this paper, a numerical model representing the heat transfer has been presented and validated using the experimental data using the nozzle system, where a nanoparticle (Al 2O3) was added to the water of the heat exchanger and the effect of the nanofluid with two volume concentrations.
Abstract: A experimental and numerical study has been carried out on the enhancement of the heat exchanged on a tube and fin heat exchanger cooled by an air flow containing water droplets by using nozzle system. A numerical model representing the heat transfer has been presented and validated using the experimental data. The cooling of air due to water evaporation upstream in a channel to the exchanger (condenser fed with hot water with different temperature) and the supplementary evaporation of droplets while impacting or crossing the exchanger leads to enhance heat exchange. As additional to enhance heat exchange, adding a nanoparticle (Al 2O3) to the water of the heat exchanger and studying the effect of the nanofluid with two volume concentrations (0.5 & 2 %). All the tests were carried out with working fluid flow rate (4, 6 and 8 L/min) and with temperature (40, 45 and 50 o C).The
TL;DR: In this paper, the authors discuss the influence of shell-side structures on heat transfer in shell and tube-heated engines. But they focus on the effect of the shell-sides on the flow of heat.
Abstract: (1983). THE INFLUENCE OF SHELL-SIDE STRUCTURES ON HEAT TRANSFER IN SHELL AND TUBE HEAT EXCHANGERS. Chemical Engineering Communications: Vol. 19, No. 4-6, pp. 325-333.
05 Jun 2006
TL;DR: In this article, experimental investigations on the oscillatory flow, heat transfer at the heat exchanger of the thermoacoustic refrigeration system were performed and significant factors that influence the heat transfer and construction of this system were identified.
Abstract: Experimental investigations on the oscillatory flow, heat transfer at the heat exchanger of the thermoacoustic refrigeration system were performed. Significant factors that influence the heat transfer and construction of this system were identified. Results were correlated in terms of Nusselt number, Prandtl number and Reynolds number to obtain a useful new correlation which was compared to the closest related existing correlations in the literature. Results show that using straight flow heat transfer correlations as done presently in a number of analyses and design of this system could result in significant errors.