The effect of pulsation on the heat transfer rates, for turbulent water stream with upstream pulsation of different amplitudes, in a double-pipe heat exchanger for both parallel and counter flows, with cold water on the shell side, was investigated. Pulsation frequencies, with using a reciprocating device, ranged up to 260 cycles per minute (up to 4.3 Hz) and 5 different displacement amplitudes...

An investigation on enhancement of heat transfer is carried out for a double pipe exchanger in which the outer wall inner provided with circumferential labyrinth passages. Rectangular and triangular cavities fixed tooth thickness, height, pitch are considered effect added structures characteristics discussed. A two-dimensional steady numerical simulation using ANSYS-FLUENT software. The flow Re...

Common approaches to the simulation of Borehole Heat Exchangers (BHEs) assume heat transfer in circulating fluid and grout to be in a quasi-steady state and ignore fluctuations in fluid temperature due to transport of the fluid around the U-tube loop. Such effects have been shown to have an impact on peak temperatures and hence operation of heat pumps systems when short time scales are consider...

a novel technique is investigated for pid controller adaptation in order to control thetemperature of a liquid-phase reactor tank by using a heat exchanger system. as for nonlinearity,time delay problems and model uncertainties introduced by the heat exchanger, an interval type-2fuzzy system (it2fs) is implemented to enhance and improve the total control performance.moreover, the fuzzy inferenc...

Generally, Central Asia is typical for regions with strong solar radiation and various natural cooling sources. The heat gain from the building envelope accounts for a large part of the cooling load there. Thus, the pipe-embedded envelope is receiving attention as a semi-active system of utilizing natural energy for cooling. In this study, the performance of the pipe-embedded envelope used in U...